ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Inorganic Chemistry  (3,763)
  • Cell & Developmental Biology  (1,486)
  • Getreide
  • 1975-1979  (5,250)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Studies on fish scale formation and resorption. I. Fine structure and calcification of the scales in Fundulus heteroclitus (Atheriniformes: Cyprinodontidae)Contribution No. 220, Belle W. Baruch Institute of Marine Biology and Coastal Research, University of South Carolina, Columbia, South Carolina 29208. (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 49-65 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Fine structure of the scales of Fundulus heteroclitus was examined by scanning and transmission electron microscopy. The concentric ridges of the scale surface were characterized by the presence of minute, highly calcified, denticles or tooth-like processes. Needle-shaped crystals of hydrox-yapatite were precipitated not only in the osseous layer but in the intimate lamellae of the fibrillary plate except in portions just below the grooves. The calcification of the osseous layer was observed to proceed by filling the matrix with patches of crystals. The fibrillary plate appeared to calcify by invasion of crystals from the upper calcified zone into spaces between collagen fibers.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Ultrastructural features of the retina and optic nerve of Strombus luhuanus, a marine gastropod (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 89-115 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The retina and optic nerve of Strombus luhuanus were examined by transmission electron microscopy in order to provide an ultrastructural basis for their electrophysiological responses, described elsewhere. The retina exhibits a distinct rhabdomeric layer and layers of cell nuclei and neuropile. These layers are comprised predominantly of three cell types that can be readily distinguished on the basis of their shape, their nuclei and cytoplasmic inclusions such as vesicles and filaments. One type of cell, apparently a photoreceptor that depolarizes in response to photic stimulation, possesses a long distal segment with microvilli; such distal segments comprise the bulk of the rhabdomeric layer. A second cell type, which appears to be supportive in function, contains a bundle of tightly packed tonofilaments that extend across the retina from the capsule to the vitreous body; this cell is quite narrow except in the region near the rhabdomeric layer, where it is expanded and wraps around the other cell types. A third type of cell possesses many short microvilli that project from its apical end into the rhabdomeric layer; it may be a second type of photoreceptor or another type of neuron. The retina also contains bundles of cilia that appear to project from a possible fourth type of cell. The layer of neuropile contains numerous processes that exhibit a variety of vesicle types and structures generally associated with synapses; these appear to play a role in mediating inhibitory and excitatory interactions between the retinal neurons. The optic nerve exhibits two populations of fiber distinguishable on the basis of mean diameter. Fibers in these two populations apparently yield “on” and “off” discharges in response to photic stimulation of the eye.
    Additional Material: 29 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Mandibular function in Galago crassicaudatus and Macaca fascicularis: An in vivo approach to Stress Analysis of the mandibleThis investigation was supported by the following: NIH Research Career Development Award (DE 00027), NIH Research Grant (DE 4531) and a NSF Research Grant (BNS 76-11924). (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 253-296 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Single-element and/or rosette strain gages were bonded to mandibular cortical bone in Galago crassicaudatus and Macaca fascicularis. Five galago and eleven macaque bone strain experiments were performed and analyzed. In vivo bone strain was recorded from the lateral surface of the mandibular corpus below the postcanine tooth row during transducer biting and during mastication and ingestion of food objects.In macaques and galagos, the mandibular corpus on the balancing side is primarily bent in the sagittal plane during mastication and is both twisted about its long axis and bent in the sagittal plane during transducer biting. On the working side, it is primarily twisted about its long axis and directly sheared perpendicular to its long axis, and portions of it are bent in the sagittal plane during mastication and molar transducer biting. In macaques, the mandibular corpus on each side is primarily bent in the sagittal plane and twisted during incisal transducer biting and ingestion of food objects, and it is transversely bent and slightly twisted during jaw opening. Since galagos usually refused to bite the transducer or food objects with their incisors, an adequate characterization of mandibular stress patterns during these behaviors was not possible. In galagos the mandibular corpus experiences very little transverse bending stress during jaw opening, perhaps in part due to its unfused mandibular symphysis.Marked differences in the patterns of mandibular bone strain were present between galagos and macaques during the masticatory power stroke and during transducer biting. Galagos consistently had much more strain on the working side of the mandibular corpus than on the balancing side. These experiments support the hypothesis that galagos, in contrast to macaques, employ a larger amount of working-side muscle force relative to the balancing-side muscle force during unilateral biting and mastication, and that the fused mandibular symphysis is an adaption to use a maximal amount of balancing-side muscle force during unilateral biting and mastication.These experiments also demonstrate the effects that rosette position, bite force magnitudes, and types of food eaten have on recorded mandibular strain patterns.
    Additional Material: 27 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Ultrastructure of the accessory glands of the Mediterranean flour mothAnagasta kuehniella (Zeller) (Lepidoptera: Pyralidae).Supported in part by U.S. Energy Research and Development Administration Contract P7603214. (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 355-391 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Five regions are recognized in the accessory glands of the Mediterranean flour moth, Anagasta kuehniella (Zeller), on the basis of cellular morphology and aggregates of secretory material in the lumen. Some variation is found in each of the posterior four regions, especially the third one. In the most anterior region (region 1) the epithelium is composed of a single type of cell, while in each of the other regions there are two classes of cells. The cells of region 1 and one class in each of the other four regions are fairly typical exocrine cells with extensive rough endoplasmic reticula. Secretion is primarily via Golgi-derived vesicles. Apocrine secretion in the form of sloughing off of the apical cytoplasm probably also occurs in all regions but is most prominent in the posterior two regions. One class of cells is very similar in morphology in each of the posterior four regions though their secretory products form characteristic aggregates in the lumen. The second class of cells (foliate cells) occurring in the posterior four segments is most notably characterized by elongate apical projections that extend out into the lumen. The apical projections contain large quantities of glycogen, some microtubules, and, in some cases, many minute mitochondria. The membrane content of the projections is also very high. In the anterior regions, the membranes are mostly fused in pairs and typically form multilayered whorls. Fusion and whorl formation decrease in the posterior regions. The cytoplasm of the foliate cells has a high organelle content including many lysosomes and mitochondria. The latter exhibit considerable polymorphism, with particular forms occurring in the different regions of the glands. The apical projections of the foliate cells are detached during copulation, presumably as the result of nervous stimulation, and become a part of the ejaculate. Replenishment of all secretory material, including the apical projections, occurs after copulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Partial regeneration of the above-elbow amputated rat forelimb. II. Electrical and mechanical facilitationSupported by the Veterans Administration Medical Research Program Project Number 7004-04 and a Medical Investigatorship Award to P.P. (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 439-451 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This investigation was undertaken to examine the observations of Becker ('72) pertaining to the electrical facilitation of partial limb regenerative responses by means of Ag-Pt wire couples applied to the limb stumps of young, forelimb-amputated white rats. Additionally, in order to examine the possible role of mechanical effects of such device implantations, we have employed uncoupled devices delivering no current or potential difference. In the present experiments, in response to coupled device implantation, cartilage and bone were actively formed in the vicinity of the Pt electrode tip. These tissues contributed to the lengthwise extension of the limb and to the partial restoration of the distal humeral extremity. In limbs bearing the uncoupled electrical devices, qualitatively similar responses were noted, but osteogenesis was diminished in extent compared to that seen in limbs bearing the active or coupled devices. It is therefore necessary to consider the role of mechanical factors in the elicitation of the observed regenerative responses. Myogenesis was enhanced in electrically stimulated limbs, but not in those rats bearing uncoupled devices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590309
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Avian scale development. VI. Ultrastructure of the keratinizing cells of reticulate scales (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 111-121 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Reticulate scales develop as radial symmetrical anlagen, in contrast to scuttate scales which appear initially as “epidermal placodes.” Unlike scuttate scales whose outer and inner epidermal surfaces elaborate β-and α-type keratins, respectively, reticulate scales elaborate only one type of epidermal surface which has been reported to give an α-type, X-ray diffraction pattern. We find that, histologically and ultrastructurally, this surface differs from either epidermal surface of scuttate scales. The keratinizing cells become filled with long interweaving bundles of α-filaments which aggregate into rather homogeneous α-fibrils. Keratohyalin granules, which have been shown to be associated with other keratinizing regions in the bird, do not form during the keratinization of reticulate scale epidermis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Ultrastructure of the parathyroid gland of the japanese lizard in the spring and summer season (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 145-155 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ultrastructure of the parathyroid glands of adult Japanese lizards (Takydromus tachydromoides) in the spring and summer season was examined. The parenchyma of the gland consists of chief cells arranged in cords or solid masses. Many chief cells contain numerous free ribosomes and mitochondria, well-developed Golgi complexes, a few lysosome-like bodies, some multivesicular bodies and relatively numerous lipid droplets. The endoplasmic reticulum is mainly smooth-surfaced. Cisternae of the rough endoplasmic reticulum are distributed randomly in the cytoplasm. Small coated vesicles of 700-800 Å in diameter are found occasionally in the cytoplasm, especially in the Golgi region. The chief cells contain occasional secretory granules of 150-300 nm in diameter that are distributed randomly in the cytoplasm and lie close to the plasma membrane. Electron dense material similar to the contents of the secretory granules is observed in the enlarged intercellular space. These findings suggest that the secretory granules may be discharged into the intercellular space by an eruptocrine type of secretion. Coated vesicles (invaginations) connected to the plasma membrane and smooth vesicles arranged in a row near the plasma membrane are observed. It is suggested that such coated vesicles may take up extracellular proteins. The accumulation of microfilaments is sometimes recognized. Morphological evidence of synthetic and secretory activities in the chief cells suggests active parathyroid function in the Japanese lizard during the spring and summer season.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Intrinsic organization of snake dorsomedial cortex: An electron microscopic and golgi study (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 185-210 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cellular populations present in dorsomedial cortex in the snakes Constrictor constrictor, Natrix sipendon and Thamnophis sirtalis are described at the light microscopic level using Nissl and Golgi preparations as well as at the ultrastructural level. This area plays a central role in cortical organization in snakes by participating in major commissural and association projections.Systematic analyses of Golgi preparations indicate that five populations of neurons are present in dorsomedial area and have a preferential laminar distribution. Layer 1 stellate cells have somata positioned in the center of the outermost cortical layer, layer 1. Their dendrites are confined to this layer. Double pyramidal cells have their somata loosely packed in layer 2. Their dendrites bear a moderate population of spines, ascending through layer 1 to the pial surface and descending partially through layer 3. Some double pyramidal cells have somata displaced downwards into the upper third of layer 3. These neurons closely resemble the layer 2 double pryamidal cells. Layer 3 stellate cells have somata positioned in the middle third of layer 3. Their dendrites extend in all directions throughout layer 3 and through layer 2 into layer 1. Finally, horizontal cells have their somata positioned deep in layer 3, near the ventricle, and dendrites aligned concentric with the ventricle.Comparison of the organization of the known afferents to dorsomedial area with the distribution of the five cell types suggests that the laminations of both afferent fibers and dorsomedial neurons places specific neuronal populations in synaptic contact with specific sets of afferents.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The extensor assembly in two species of opossum, Philander opossum and Didelphis marsupialis (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 337-345 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In considering primate and hominoid phylogeny, the fundamental position assigned to opossums is explained partially by the characteristic morphology of their hands and feet. One of the main functional features of the human hand is the ability to make a stabilized arch of the finger. Because the extensor assembly plays a key role in establishing an arched finger, the extensor systems of the digits of both the hands and feet were studied in two species of opossum, Philander opossum and Didelphis marsupialis.In the foot, two extensor tendons join in each toe to form one tendinous plate, which inserts onto the base of the second phalanx. Lumbricals join this plate along the tibial side, and interosseus insertions are found, although a true interosseus wing is lacking. At the proximal interphalangeal level, a terminal tendon takes its origin from this tendinous plate. This terminal tendon is oval in cross-section and contains elastic structures. Oblique bands arise from this terminal tendon and run proximally along the proximal interphalangeal joint inserting onto the base of the first phalanx. There are elastic structures in the flexor tendon on the dorsal side near its site of insertion.In the hand, the main extensor tendons are arranged differently and the interossei contribute substantially to the extensor assembly. Otherwise, the extensor assembly of the hands and feet are quite similar. The function of the so-called paratendinous intravaginal flexors is discussed as are evolutionary aspects of the extensor assembly.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620201
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Comprehensive schemata on the histology of the liver with consequences in terminology (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 211-219 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: New schemata of the liver are presented to discuss the combination of the three kinds of liver lobules known until today in a chalk-talk-manner. Terminology is also discussed. Further investigations are needed involving the construction and the vascular pattern of compound lobules of the three individial lobules of the liver in different species.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    A comparative study of the differentiation and involution of the mullerian duct and wolffian duct in the male and female fetal mouse (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 175-209 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The present investigation has examined the ultrastructural differentiation of the genital ducts of both sexes of fetal mice. The emphasis of observations was placed on the phenomenon of morphogenetic cytolysis, particularly during the critical periods of Wolffian duct stabilization and Mullerian duct involution.Both developing and regressing genital ducts evidence extensive cytolysis. Autophagy appears to be the mechanism of morphogenetic change in the developing male Wolffian duct. Autophagy, heterophagy, and degeneration in situ are all prominent cytolytic activities in female Wolffian duct involution. The developing female Mullerian duct undergoes extensive morphogenetic remodeling by the mechanisms of autophagy, heterophagy, and degeneration in situ. In the male Mullerian duct, autophagy, heterophagy, and degeneration in situ are also prominent. In addition, whole degenerated epithelial cells are extruded from the duct early in regression which may be related to the transformation of periductal mesenchymal cells into an “epithelioid cell cuff” which does not form around the regressing Wolffian duct. The formation of this mesenchymal condensation surrounding the duct is also accompanied by the protrusion of Mullerian epithelial cell cytoplasm into the mesenchymal cells. These observations may evidence a complex epithelial-mesenchymal interaction occurring during male Mullerian duct involution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Editorial (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 311-311 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Structure and carbohydrate histochemistry of the intestine in ten teleostean species (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 343-359 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology and carbohydrate histochemistry of ten teleostean intestines are compared. Although there is an absence of regional differentiation seen in higher vertebrates, specializations in some species occur in the form of intestinal swellings, pyloric ceca and recta, the latter separated by a valve. The intestinal lumen is lined by a simple columnar epithelium interspersed with goblet cells; multicellular intestinal glands are absent. Thick basement membranes seen in centrarchids and Perca flavescens closely resemble the stratum compactum found in the lamina propria of esocids. Granular cells, which vary in number from species to species, are often seen in the mucosa and submucosa but less frequently in the muscularis. In species with intestino-rectal valves, a rectum is easily defined by the abrupt appearance of lower mucosal folds, more goblet cells and a thicker muscularis. In the remaining species the above features appear gradually in the distal intestine. Goblet cells show species variations in localization of epithelial mucosubstances, which in broad terms are recognized as sulfomucins, sialomucins and neutral mucosubstances. In both proximal and distal intestines the majority of goblet cells contain sialomucin although small amounts of sulfomucin are also often present. In species without intestino-rectal valves, no changes in carbohydrates occur between proximal and distal intestines. The possible significance of the heterogeneous character of digestive tract mucosubstances is discussed.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    The morphology of the sex pheromone gland in Drosophila grimshawi (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 177-183 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology of a sex pheromone-producing gland found in the abdomen of Drosophila grimshawi males was studied by light and electron microscopy. This gland, consisting of two intra-anal lobes, contains cells that resemble those of other insect pheromone glands. However, in contrast to many other insect pheromone glands that release pheromone through the cuticle, cells of the intra-anal lobes secrete into a canaliculi-duct system that empties into the anal region. The liquid secretory product flows along the surface of the intra-anal lobes and is brushed onto the substrate by fingerlike projections on the lobes' surfaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Ultrastructure of the sacculus and lagena in a moray eel (Gymnothorax sp.) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 241-256 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ultrastructure of the sacculus and lagena of a moray eel, Gymnothorax sp., was investigated using scanning and transmission electron microscopy. Particular emphasis was placed on the orientation of the sensory hair cells and on the ultrastructure of the sensory cells. The ciliary bundles on the sensory hair cells are of several types, each having a different size relationship between the kinocilium and stereocilia. The cell bodies of the sensory cells are similar to the mammalian type II sensory cell. There were no apparent differences in the cell bodies between sensory cells with different ciliary bundles.Hair cell orientation patterns on the saccular and lagenar maculae differ from patterns found in other fishes. The posterior side of the saccular macula in Gymnothorax has cells oriented dorsally and ventrally, as is typical in other non-ostariophysan species. The anterior end of the saccular macula has alternating groups of anteriorly and posteriorly oriented cells, a situation that differs from the more typical pattern in which anteriorly oriented cells are found on the ventral side of the macula while posteriorly oriented cells cover the dorsal side of the macula. The orientation of cells on the lagena includes ventral cells that are located above a group of dorsally oriented cells. In many other non-ostariophysans, ventrally oriented cells are generally posterior to the dorsally oriented cells.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    The blood supply of muscle spindles in some mammals and the pigeon (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 323-335 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The blood supply of muscle spindles was studied in serial cross sections in macaque, cat, rabbit, guinea pig, mouse and pigeon muscles which had been incubated in a medium containing 3,3′ diaminobenzidine. Lumina of blood vessels were recognized by the reaction product that was localized within erythrocytes. The outer capsule was well vascularized, but few or no capillaries were seen in the periaxial space. The inner spindle capsule, which closely invests the axial bundle, was rarely contacted by periaxial capillaries at the equator and juxtequator. Capillaries occurred more frequently adjacent to intrafusal fibers at the polar region and beyond the end of the outer capsule. Shorter diffusion distances and, usually, higher capillary densities were found at the polar region than at the spindle midsection. This suggests that transcapillary exchange at the polar segment is nearer to conditions prevalent in extrafusal muscle than elsewhere in the spindle, provided the inner and outer capsules are not less permeable at the poles than at the midsection. Differences in blood supply among mammalian species appear to be related to receptor size.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Origin and fate of germ cells in male and female embryos of Haplothrips verbasci (Osborn) (Insecta, Thysanoptera, Phlaeothripidae) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 160 (1979), S. 323-343 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Comparison of germ cells in male and female embryos of the arrhenotokous thrips, Haplothrips verbasci, yields the following observations: A mean of 11 cleavage energids enter the posterior pole plasm of the egg after the sixth cleavage division and apparently become pole cells when they take up polar granules in their cytoplasm. The cells proliferate asynchronously prior to and during anatrepsis to yield a mean of 36 germ cells in male embryos and 31 in females. Visible sexual differentiation of germ cells begins during germ band elongation and is completed shortly after the appearance of appendages. Female germ cells are larger than those of the males and may contain two nucleoli. The germ cells separate into two groups just before katatrepsis and mesodermal cells collect about these to form the primary epithelial sheaths of the gonads and the primordia of the gonoducts shortly after revolution is completed. Each gonad contains a mean of 13 germ cells in male embryos and 7 in females - a number that persists until mitosis resumes after hatching. During ketatrepsis, a mean of 11 germ cells in male embryos and 2.6 in females fail to be enclosed within the gonads, become dispersed in the yolk and perhaps transform into vitellophages.Germ cell development in H. verbasci embryos resembles similar events taking place in psocid embryos, providing additional evidence for a close phylogenetic relationship between Thysanoptera and Psocoptera.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051600305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Presence and development of a sensory formation in the eyestalk of the crayfish, Astacus leptodactylus (Nordmann, 1842), during its embryonic, larval and adult lifeThis study was partially sponsored by C.N.R.S. (France) under grànt A.T.P. International 1976-2602. (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 39-51 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A sensory papilla is described in the eyestalk of the crayfish Astacus leptodactylus during the last embryonic stages and during larval stages by light microscopy. This region was also investigated with the scanning electron microscopy, which showed sensory hairs in the postmolt adult; they disappear during intermolt and premolt. Simultaneous cyclic changes in hair papillae are observed in the hypodermis. The possibility of a chemoreceptive function is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Membrane production and yolk degradation in the early fly embryo (Calliphora erythrocephala meig.): An ultrastructural analysis (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 53-77 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Formation of nuclear envelopes during the last cleavage mitosis and the formation of the cell membranes during the cellularization of the blastoderm have been studied ultrastructurally in the blowfly egg. Dense bodies arising from yolk granules by budding could contain membrane material destined to be incorporated into the new membranes of the blastoderm. The presence of transitional structures indicates that these bodies can be converted into dark multivesicular bodies. Large amounts of endoplasmic reticulum are found around the mitotic nuclei. Clusters or branched chains of vesicles associated with this are interpreted as evidence for the formation of endoplasmic reticulum by the breakdown of dark multivesicular bodies. Nuclear envelopes of mitotic daughter nuclei probably originate from endoplasmic reticulum. The egg contains both intranuclear and extranuclear annulate lamellae.The main events of cytokinesis are furrow initiation and cell membrane growth during the slow first phase, but probably only cytokinetic movement during the rapid second phase. On the assumption that cell membrane growth occurs by incorporation of complete membrane pieces, the addition of coated vesicles and/or light multivesicular bodies is definitely most probable. Some intermediate profiles indicate that light and dark multivesicular bodies are related. The membrane needed for second phase cytokinesis could well be provided by the unfolding of surface microvilli and protuberances of the furrow canal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Countercurrent blood vessel arrangement in beaver (Castor canadensis) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 169-175 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The vascular anatomy of five beavers (Castor canadensis) was studied by dissection and injection of arteries and veins with vinyl acetate. There is extensive countercurrent arrangement of arteries and veins distal to and including the common iliac artery and veins. Two types of countercurrent vessels occur (1) a venae comitantes type in which two or three veins surround a central artery, and (2) a modified rete type. The retia are located proximal to the large flat tail and the webbed hind feet. Two bypass veins are described for the feet and tail and the significance of these structures in temperature regulation is stressed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610301
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Ultrastructure of the type “B” cells in the rectal pad epithelium of Locusta migratoria (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 221-232 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The electron microscopical structure of the type “B” cells in the rectal pad epithelium of Locusta is described. The type “B” cells occur singly in the distal region of the rectal pad epithelium. They are characteristically goblet shaped and join with contiguous type “A” or rectal pad cells, near the apical surface by means of a restricted region of septate desmosomes. Type “B” cells possess a microvillate apical membrane, with the villi arranged as a rosette overlying the apical inaginations of adjacent type “A” cells.Large numbers of microtubules and vacuoles of various sizes containing an assortment of inclusions are present in the apical region of the type “B” cells. Many of the microtubules insert distally on hemidesmosomes located in the apical plasma membrane. Rough endoplasmic reticulum and mitochondria are also present but neither are abundant. The possible significance of these findings is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    The development of amphids and amphidial glands in adult Syngamus trachea (Nematoda: Syngamidae) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 160 (1979), S. 299-321 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Nematode amphids are a pair of lateral cephalic sense organs, each comprising a group of sensory endings terminating in a cuticle-lined pit. In Syngamus trachea, a parasite of birds, each amphid is surrounded by two non-nervous supporting elements, a large gland cell basally and a smaller supporting cell anteriorly. The amphidial glands display high levels of secretory activity from five to six days postinfection. Secretory material is discharged through the lumen of the sense organ onto host tissue. The ultrastructure of amphids and amphidial glands has been investigated in newly moulted, immature and mature adults to trace the development of glandular activity and its effect on amphid-amphidial gland relationships. In newly moulted adults, the glands have very low levels of secretory activity and appear to act only as supporting cells to the amphids. As secretory activity increases, the gland cell membrane surrounding the sensory endings is elaborated into a reticulum which probably forms the secretory surface. In mature adults the amphid pit is swollen and filled with secretion; the sensory endings are relegated to the periphery of the lumen. It is suggested that amphidial glands develop from typical supporting cells, but acquire a new role possibly associated with parasite attachment.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051600304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Histochemical and ultrastructural features of the aorta of the slug (Limax maximus) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 1-21 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: As a part of a continuing study of unusual molluscan tissues, the “chondroid” tissue (Hyman, '67) associated with the anterior and posterior aortae of the slug (Limax maximus) was examined by light and electron microscopy. Unlike the odontophoral tissue of this species (Curtis and Cowden, '77), the “chondroid” tissue comprising the adventitial layer of the aorta consists of large, glycogen-filled cells with characteristic arrays of pores in their plasma membranes resembling those of the “globular” cells (Rogers, '69; Fernandez, '71); “fibrocytes” (Nicaise et al., '66; Baleydier et al., '69; Nicaise, '73); “Blasenzellen” or “Leydig” cells (Wondrak, '69; Stang-Voss, '70; Buchholz et al., '71; Stang-Voss and Staubesand, '71; Wolburg-Buchholz, '72); or “pore” cells (Sminia, '72; Beltz, '77) of other mollusks. The anterior and posterior aortae are very similar in organization, except that the anterior aorta is larger in diameter; its wall is thinner; and it lacks calcification. Both the anterior and posterior aortae possess a loosely organized (incomplete) endothelial layer surrounded by two layers of innervated smooth muscle. The smooth muscle cells possess fibrous surface specializations resembling hemidesmosomes as well as large numbers of tubular or rounded vesicles in association with their plasma membranes. Blood cells (amoebocytes) containing large glycogen deposits and distinctive membrane-enclosed cytoplasmic inclusions can be found occasionally in the walls of the vessels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    The hind limb musculature of the brown kiwi, Apteryx australis mantelli (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 160 (1979), S. 33-73 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The most complete account of the hind leg muscles of the kiwi was published a century ago by Sir Richard Owen, in his seventy-fifth year. This extensively-cited work has several omissions and errors, and while certain of these were corrected by subsequent authors, sufficient uncertainty remains to warrant a reinvestigation. In the present study a detailed description of the hind leg musculature is given, based upon dissections of two frozen specimens. An indication of the possible function of each muscle is given by assessing its size, action, and fiber-arrangement, together with tentative data on the relative abundance of twitch and tonus fibers.The correlation between surface features of bones and muscle attachments is investigated with a view to interpreting palaeontological material. Although the limb and pelvic bones are marked by numerous features which suggest muscle attachments, relatively few can be positively identified with specific muscles. Only 23% of the muscle origins and insertions can be identified, and, with three possible exceptions, no indication of relative size is given by the scars. The possibility of being able to reconstruct the musculature of the kiwi from its skeletal anatomy, much less that of its extinct relatives, is remote.
    Additional Material: 26 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051600105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    A model to explain the posterior limit of the bite point in reptiles (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 160 (1979), S. 165-168 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A biomechanical model of the jaw mechanism in some reptiles is presented. Symmetrical muscle activity that produces equal forces on both sides of the head is assumed. The model predicts the position of the most posterior bite point and offers a functional explanation for this prediction. Turtles are used to illustrate the idea.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051600204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 160 (1979) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051600201
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Organization of nucleus rotundus, a tectofugal thalamic nucleus in turtles. I. Nissl and Golgi analyses (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 160 (1979), S. 121-141 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This study consists of a detailed cytoarchitectonic and Golgi analysis of a major tectofugal thalamic nucleus in the red-eared turtle, Pseudemys scripta elegans. Neurons in nucleus rotundus have a unimodal soma size distribution and a common dendritic branching pattern. They have long dendrites which undergo sparse, dichotomous branchings and contribute to dendritic fields that cover a third to half the dimensions of the nucleus. Spicules, 1-2 μ long, and complex appendages, 5-20 μ long, are found with low density on many dendrites in Golgi-Kopsch material. A few cells have beaded dendritic processes. Three cytoarchitectural regions can be differentiated in nucleus rotundus: a shell, a cell-poor region and a core. The shell is a monolayer of somata forming the peripheral boundary of most of the nucleus. The cell-poor region forms a thin zone concentric with and internal to the shell. Shell cells send some of their dendrites concentrically within this zone and others radially into the core region. Core neurons are dispersed within the neuropil of the nucleus and usually have spherical dendritic fields. However, peripheral core neurons have asymmetrical fields, so their dendrites do not extend beyond the shell. Caudomedial and central subregions of the core can be defined on the basis of neuronal density and cytology. Somata in the caudomedial area of the core are densely packed and have slightly darker staining cytoplasm than those in the central subregion. However, their dendrites are similar to those of the central core neurons. There is extensive dendritic overlap between the two subregions.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051600202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Glycogen metabolism in the prelaid chick embryo (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 23-38 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Glycogen metabolism has been studied during the development of the early chick embryo, at the cytochemical and ultrastructural levels. Two waves of glycogen synthesis and breakdown have been found. In the first, free clusters of glycogen particles are synthesized at late oogenesis. These clusters are found later in invaginations of the membrane of vesicles containing a floc-cular material (FLOV). The glycogen clusters are degraded there during ovulation and the first hours in the oviduct. The second wave of glycogen synthesis begins before cleavage, reaching a maximum at mid-uterine age. This second wave occurs in another type of vesicle (GLYV), which eventually disintegrates releasing free clusters of glycogen granules. This glycogen is degraded in membranous structures containing a floccular material, as in the first wave of degradation. The degradation ends at the late uterine stages, and at the same time numerous ribosomes are formed. This period corresponds to area pellucida formation, which probably depends on the energy liberated during the second wave of glycogen degradation.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Studies on the tardigrades. IV. Fine structure of the hindgut of Milnesium tardigradum doyère (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 79-109 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The hindgut of the semi-terrestrial tardigrade, Milnesium tardigradum was examined with light and electron microscopy. The hindgut consists of a cloaca and an anterior hindgut. It is delineated anteriorly by the pylorus into which four Malpighian tubules empty and posteriorly, by a broad cloacal slit. A single oviduct enters the hindgut at the junction between the cloaca and the anterior hindgut. Two pairs of muscles insert on the cloaca and anterior hindgut respectively. Electron microscopic observations demonstrate that the anterior hindgut is a specialized transporting epithelium. The luminal surface is covered by a thin layer of cuticle which penetrates into channel-like invaginations. Numerous mitochondria are concentrated apically. The basal and lateral surfaces are also folded. The cells are joined apically by deep tight junctions and a simple basal lamina lines the entire hindgut. The cloaca which receives the contents of the gut and Malpighian tubules as well as gametes of the reproductive tract is a transitional organ that exhibits several characteristics of the hypodermis and anterior hindgut. The cuticle of the cloaca changes sequentially from the complex structure of the integument to a simple layer of the anterior hindgut. The function of the hindgut is discussed with emphasis on the possible response of the anterior hindgut to a hypoosmotic habitat, evaporative water loss during the induction of anhydrobiosis and low oxygen tension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    The fine structure of blood follicles in the earthworm genera Amynthas and Lumbricus (Annelida: Oligochaeta) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 123-143 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Blood follicles of the earthworm Amynthas are hemoglobin-containing, sac-like dilatations of blood vessels which connect to the general circulation. Grape-like clusters of follicles are found posterior to the pharynx, among tufts of micronephridia, and single follicles are located among cells of the pharyngeal gland. In Lumbricus, follicles take the form of simple swellings and irregular-shaped diverticula of nephridial capillaries.The fundamental structure of the wall of follicles and of vessels in both genera is the same and consists of two layers: an extracellular vascular lamina and an outer (coelomic) covering of smooth muscle-like myoperithelial cells. Hemocytes may be free and circulating or they may facultatively attach to the vascular lamina as littoral cells, constituting an incomplete endothelium-like surface. Hemocytes that appear to be in the process of attaching or detaching are rounded, while adherent cells are flattened and elongate. Free and littoral hemocytes actively endocytose packets of circulating extracellular hemoglobin.Hemocytes within follicles possess radiating cell processes which also endocytose hemoglobin. Although these cells were presumed to secrete hemoglobin, staining with 3,3′-diaminobenzidine confirms the presence of hemoglobin only within pinosomes and not within protein-synthesizing or packaging organelles. The presence of hemosiderin-like bodies suggests that follicular hemocytes catabolize hemoglobin.Blood follicles apparently provide a means of significantly increasing cell-surface area for hemoglobin processing, without substantially increasing the volume and pumping load of the circulatory system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610201
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    The mouthparts of female Corethrella brakeleyi and C. wirthi (Diptera: Chaoboridae) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 157-167 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The mouthparts of female Corethrella brakeleyi and C. wirthi were studied using light and electron microscopy. Mandibles, hypopharynx and labium are highly sclerotized and are modified for obtaining blood meals. All structures were larger in C. brakeleyi than in C. wirthi except mandibular and hypopharyngeal teeth; these were smaller and more numerous in C. brakeleyi. The labium of both species terminates in peg-like structures which are similar to those reported from several genera of mosquitoes. Sensillae on the second segment of the maxillary palps appear to be identical to those described in both biting and nonbiting male and female blackflies.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    The structure of the canary's incubation patch (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 425-451 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The gross morphology, histology and ultrastructure of the canary's incubation patch and the ventral apterium from which it arises are described. The apterium is vascularized by pectoral, external mammary, incubation, and prepubic arteries. It is innervated by cutaneous branches of spinal nerves. It has a surface area of 6 cm2.Its epidermis is a stratified squamous epithelium with basal, intermediate, transitional and cornified layers. Cells in the stratum germinativum contain a normal array of organelles, but are characterized by tonofilaments, desmosomes and interdigitating surfaces. Cellular organelles disappear in the stratum transitivum and are replaced by large vacuoles and keratohyalin bands. Nonmyelinated nerve fibers are abundant in the stratum germinativum.The dermis consists of (1) an avascular layer of dense collagen subjacent to the epidermis and containing many nonmyelinated nerves, and (2) an underlying layer of areolar connective tissue containing blood vessels, lamellar corpuscles and nerves. A layer of coarse elastic fibers, reinforced by collagen and smooth muscle, separates the dermis from subcutaneous tissue.In contrast to the ventral apterium, the incubation patch is featherless and visibly hypervascular and edematous. Its epidermis is both hypertrophic and hyperplastic. Large spaces separate cells in the stratum germinativum. The visible hypervascularity is due to hyperemia and increased number and size of blood vessels in the dermis. Visible edema is due to the accumulation of fluid interstitially. Although no histological differences exist among various regions of the ventral apterium, such differences are present in the incubation patch.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620309
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Cell death and optic fiber penetration in the optic stalk of the chick (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 67-75 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The role of dying cells in the optic stalk in relation to retinal fiber migration was investigated in the chick embryo. Cell death was analysed at various stages of development by counting pycnotic nuclei and also by the Gomori acid phosphatase reaction, while nerve fibers were visualised by the Bodian method. A wave of cell death, beginning in the neural retina at stage 18 and advancing with time through the stalk towards the diencephalon, occurred simultaneously or slightly prior to differentiation and migration of ganglion cell axons. Cell death stopped and gliogenesis occurred in the stalk after penetration by retinal fibers. Cell death occurred in the stalk even when fiber penetration was prevented by optic cup ablation. In this case, necrosis ensued until almost complete degeneration of the stalk, usually within three days after the operation, and gliogenesis did not occur. As the stalk degenerated, its cells became heavily pigmented. These observations suggest that the onset of cell death in the optic stalk is determined prior to and independently of retinal fiber penetration. On the other hand, cessation of cell death and subsequent gliogenesis occur only in the presence of ingrowing optic fibers.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Ultrastructure of an exocrine dermal gland in the gills of the grass shrimp, Palaemonetes pugio: Occurrence of transitory ciliary axonemes associated with the sloughing and reformation of the ductule (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 281-307 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Exocrine dermal glands, comparable to the class 3 glandular units of insects, are found in the gills of the grass shrimp, Palaemonetes pugio. The dermal glands are composed of three cells: secretory cell, hillock cell and canal cell. Originating as a complex invagination of the apical cytoplasm of the granular secretory cell, a duct ascends through the hillock and canal cells to the cuticular surface. The duct is divisible into four regions: the secretory apparatus in the granular secretory cell, the locular complex, the hillock region within the hillock cell and the canal within the canal cell. A tubular ductule is contained within the latter two regions. As the ductule ascends to the cuticular surface, its constitution gradually changes from one of a fibrous material to one which possesses layers of epicuticle. During the proecdysial period, the ductule is extruded into the ecdysial space and this is followed by the secretion of a new ductule. Temporary ciliary structures, located near the secretory apparatus of the secretory cell, are associated with the extrusion and reformation of the ductule. Characterized only by a basal body and rootlets throughout most of the intermolt cycle, the ciliary organelles give rise to temporary axonemic processes which ascend through the ductule toward the ecdysial space at the onset of proecdysis. Subsequently, the old ductule is sloughed off and a new ductule is reformed around the ciliary axonemes. Following this reformation, the ciliary axonemes degenerate. The function of cytoplasmic processes, derived from the apical cytoplasm of the secretory cell, is also discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Ordered membrane particles in rhabdomeric microvilli of the housefly (Musca domestica L.) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 161 (1979), S. 309-321 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Rhabdomeric microvilli of the housefly were freeze-fractured (FF) and thin sectioned (TS) for ultrastructural examination. Ordered files of closely packed membrane particles (82 Å wide, 250 Å long) were seen (FF) on the microvillar membrane (usually E face). The long axis of each particle was canted about 45° to that of the microvillus. Occasionally particles in this array appeared on the P face. It is hypothesized that ordered particles may represent either a photopigment precursor stock, a second photolabile pigment, or the newly discovered sensitizing, UV-absorbing, photostable visual pigment. In the underlying membrane leaflet (P face) were found spherical (85 Å diameter) unoriented particles in a concentration of about 6,000/μm2. The size, shape and density of these structures are compatible with those of rhodopsin particles. These particles also covered the basal area of each microvillus. The findings from TS material were difficult to correlate with those from FF replicas. At high magnification the former showed that the plasma membrane of the transected microvillus is composed of spherical, hollow subunits (averaging 43 Å diameter), sometimes fused to form double, 86 Å units. These substructures were closely packed and continuous around the microvillus. This beaded plasma membrane, in rare cases, was doubled around the microvillus. In other instances the plasma membranes were continuous between neighboring microvilli. The physiological implications of these ultrastructural features are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051610305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Interactions between Tectal Radial Cells in the Red-Eared Turtle, Pseudemys scripta elegans: An Analysis of Tectal Modules (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 17-36 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The optic tectum is a major subdivision of the visual system in reptiles. Previous studies have characterized the laminar pattern, the neuronal populations, and the afferent and efferent connections of the optic tectum in a variety of reptiles. However, little is known about the interactions that occur between neurons within the tectum. This study describes two kinds of interactions that occur between one major class of neurons, the radial cells, in the optic tectum of Pseudemys using Nissl, Golgi and electron microscopic preparations.Radial cells have somata which bear long, radially oriented apical dendrites from their upper poles and short, basal dendrites from their lower poles. They are divided into two populations on the basis of the distribution of their somata in the tectum. Deep radial cells have somata densely packed in the stratum griseum periventriculare. Their plasma membranes form casual appositions. Middle radial cells have somata scattered throughout the stratum griseum centrale and stratum fibrosum et griseum superficiale and do not contact each other. The apical dendrites of both populations of radial cells participate in vertically oriented, dendritic bundles. The plasma membranes of the dendrites in these bundles form casual appositions in the deeper tectal layers and chemical, dendrodenritic synapses within the stratum fibrosum et griseum superficiale. The synapses have clear, round synaptic vesicles and slightly asymmetric membrane densities. Thus, radial cells interact via both casual appositions and chemical synapses.These interactions suggest that radial cells may form a basic framework in the tectum. Because both populations of radial cells extend into the stratum fibrosum et griseum superficiale and stratum opticum, they may receive input from some of the same tectal afferent systems. Because the deep radial cells alone have somata and dendrites in the deep tectal layers, they may receive additional inputs that the middle radial cells do not. Neurons in the two populations interact via chemical dendrodendritic synapses, thereby forming vertically oriented modules in the tectum.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    The telotrophic-meroistic ovary of megaloptera. I. The ontogenetic development (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 37-65 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Sialis flavilatera L. (Sialidae, Megaloptera) has telotrophic-meroistic ovarioles. The germ cells of the tropharium are organized into two distinct tissues, the central syncytium and the germ cell tapetum. The central syncytium consists of nurse cell nuclei embedded in a common cytoplasm which is rich in ribosomes and mitochondria. Cell membranes are totally absent. The germ cell tapetum surrounds the syncytium and consists of a monolayer of cells, each of which is connected with the central syncytium by an intercellular bridge. The oocytes differentiate from basal tapetum cells by previtellogenic growth. Their nutritive cords remain connected to the central syncytium by the intercellular bridge.Ovariole development starts soon after hatching with the immigration of germ cells into the ovariole-anlagen and is finished during pupal stages 23 months later. In apical regions of each tropharium, mitoses occur throughout larval life. The descendants enter the prophase of meiosis which lasts until pre-vitellogenesis; thus, a differential gradient of position and time is established. About 12 months after hatching, the central syncytium arises at the base of the tropharium from a membrane labyrinth in which intercellular bridges are entangled. Evidence is presented that endopolyploidization does not occur during germ cell differentiation.Finally, the results are compared with those found in Hemiptera and polyphage Coleoptera. The great diversities are interpreted as an indication for a polyphyletic origin of the telotrophic ovary.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Sense organs on the antennal flagellum of the mimosa webworm, Homadaula anisocentra (Lepidoptera, Glyphipterygidae) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 163-173 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Five different types of sense organs were found on the antennal flagellum of Homadaula anisocentra. These were (1) tactile hairs; (2) thick-walled chemoreceptors; (3) thin-walled chemoreceptors of several kinds; (4) styloconic chemoreceptors and (5) small chemoreceptor pegs in shallow depressions. No coeloconic sense organs were seen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Growth and differentiation of secondary malpighian tubules in the cockroach, Periplaneta americanaThis work was submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biology at Northwestern University and was supported in part by the National Institutes of Health under Research Grants AM 14993, AM 14993, AM 19189, and FR 7028 to James L. Oschman and Betty J. Wall.An abstract of this work was published in J. Cell. Biol., 75: 32a, 1977. (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 389-411 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Four differentiated Malpighian tubules (primary tubules) extend from the junction of the midgut and hindgut in newly hatched Periplaneta americana. Secondary tubules begin to develop near the base of the primary tubules before hatching and successive nymphal molts. The newly initiated tubules undergo cell division and extensive elongation through the middle of the following intermolt period. During this time, the cells of the distal, middle, and lower middle tubule regions are surrounded by a cellular sheath, have few cytoplasmic processes extending along their basal surfaces, have a small or nonexistent lumen, and contain extremely dilated cisternae of endoplasmic reticulum. The cellular sheath differentiates into the muscle which coils around the mature tubule. Tubules which begin development toward the end of one intermolt period begin to undergo cytodifferentiation toward the end of the next intermolt period. By the middle of an additional intermolt period, the basal infoldings and microvilli of cells in the distal, middle, and lower middle regions have the conformations typical for those regions in differentiated tubules; granular concretions and stellate cells are present within the middle region of the tubule.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    The structure and distribution of external sense organs in newly hatched and mature earthworms (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 1-15 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Fully mature adult Eisenia foetida sensory buds are abundant on the prostomium and the first segment. In subsequent segments they are restricted to the anterior half where they form a single row aligned with the setae and encircling the worm. In the more posterior regions of the worm the buds are widely separated and fewer. The surface of each bud is a raised circular or oval area from which 15 to 100 so-called sensory hairs arise, being cylindrical and apparently flexible. The number of these projections decreases toward the posterior end of the worm.In worms newly emerged from egg cocoons, the general pattern of distribution and external form of sensory buds resembles that of adults, but the buds are much fewer and smaller than in adults. Although these worms emerge with their definitive adult number of segments, new buds and additional sensory projections are formed during post hatching development.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Morphology and distribution of Type II supraependymal cells in the third ventricle of the guinea pigSupported in part by NIH Grant RR-05387-13. (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 67-79 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The distribution and morphology of phagocytic (Type II) supraependymal cells residing within the third ventricle of the guinea pig were investigated by scanning electron microscopy. Type II supraependymal cells were restricted to nonciliated regions of the ventricle. They were most numerous on the choroid plexus, abundant within the infundibular recess and were present on the ventricular floor in the region of the median eminence. Morphologically, they were characterized by a soma from which pseudopodia-like processes extended to the subjacent ependyma. Type II cells varied in configuration according to their location. Those residing on the choroid plexus typically had irregular somas and possessed processes that generally terminated in finger-like extensions. In contrast, cells on the ventricular floor and within the infundibular recess were stellate and possessed processes that terminated in fan-like cytoplasmic expansions. There were no differences noted in the frequency, distribution or morphology of Type II supraependymal cells in male and female animals. Furthermore, cell frequency did not appear to vary in relation to the estrous cycle. The data suggest that the pleomorphism exhibited by Type II supraependymal cells may reflect adaptations to diverse environmental conditions present within different regions of the third ventricle.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    The intranuclear helices of Euplotes: Their substructure, localization, and apparent migration to the cytoplasm (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 81-87 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Study of the fine structure of the macronucleus in Euplotes eurystomus, a ciliate protozoon, during various stages of the cell division cycle has yielded new information about intranuclear helices. They are frequently observed at the periphery of chromatin bodies or next to the nuclear envelope, and they appear to be a constituent of nucleoli. The fibril that forms a helix is about 11-15 nm thick, and torus profiles of helices cut in cross section are about 35 nm in diameter. In substructure the helix is composed of a thin strand 3-5 nm thick which is coiled to form the 11-15 nm fibril; so the helix is a super-coiled structure. The intranuclear helices are present in the macronucleus throughout the cell cycle. They do not show obvious changes of relative abundance nor changes of relative localization in the nucleus, with one exception: they were never observed in the diffuse zone of replication bands. Evidence is presented indicating that nuclear helices migrate to the cytoplasm through nuclear pores. Although the chemical composition of the Euplotes intranuclear helices is unknown, information in the literature on similar helices in Amoeba indicates that they contain RNA and not DNA. The observations on Euplotes helices are consistent with a concept of “packaged” RNA for transport to the cytoplasm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Structure of the shell and tertiary membranes of eggs of softshell turtles (Trionyx spiniferus) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 131-143 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Eggs of the turtle Trionyx spiniferus are rigid, calcareous spheres averaging 2.5 cm in diameter. The eggshell is morphologically very similar to avian eggshells. The outer crystalline layer is composed of roughly columnar aggregates, or shell units, of calcium carbonate in the aragonite form. Each shell unit tapers to a somewhat conical tip at its base. Interior to the crystalline layer are two tertiary egg membranes: the outer shell membrane and the inner shell membrane. The outer shell membrane is firmly attached to the inner surface of the shell, and the two membranes are in contact except at the air cell, where the inner shell membrane separates from the outer shell membrane. Both membranes are multi-layered, with the inner shell membrane exhibiting a more fibrous structure than the outer shell membrane. Numerous pores are found in the eggshell, and these generally occur at the intersection of four or more shell units.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Afferent and efferent components of the facial nerve in the bullfrog (Rana catesbeiana)This work was supported by grants from the National Aeronautics and Sapace Administration: NAS 9-15213 and NSG 7441. (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 245-252 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The afferent and efferent components of the facial nerve were traced within the brain stem of Rana catesbeiana, using three different neuroanatomical techniques. Primary afferent fibers could be traced to the spinal tract of trigeminal nerve and to fasciculus solitarius as far caudally as the first or second spinal segment, using silver degeneration methods. Cobalt filling of the entire nerve showed the same distribution of afferent fibers, as well as the filling of the cells within the mesencephalic nucleus of trigeminal, indicating the origin of a proprioceptive component of the facial nerve. Cobalt iontophoresis and horseradish peroxidase experiments showed that the motor nucleus of the facial nerve was located just ventral to the fourth ventricle, and caudal to the motor nucleus of trigeminal. The distribution of afferent fibers to fasciculus solitarius and the spinal tract of trigeminal is similar in some respects to the distribution of afferent fibers from the trigeminal and vagal nerves in the bullfrog. The afferent fibers from the three cranial nerves are found as far caudally in the brain stem as the second spinal segment.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Tooth crown morphology in caecilians (Amphibia: Gymnophiona) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 331-341 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology of tooth crowns is variable inter-specifically among caecilians. Cusp number and shape, crown dimensions, and crown curvature characterize various species and have both functional and phylogenetic implications. Ichthyophis, Uraeotyphlus, Hypogeophis, and Geotrypetes have bicuspid teeth; Dermophis, Gymnopis, Caecilia, and Typhlonectes monocuspid. Crown morphology as revealed by scanning electron microscopy is associated with prey grasping and, in one case, possible specialization of prey type.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 160 (1979) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051600101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Chemoreceptors in the cibario-pharyngeal pump of the cabbage looper moth, Trichoplusia ni (Lepidoptera: Noctuidae) (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 160 (1979), S. 7-15 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The structure of contact chemoreceptors in the cibariopharyngeal pump of the moth Trichoplusia ni (Lepidoptera: Noctuidae) is described. Two types of receptors designated A and B are located on the floor of the pump. Two groups of 9-12 A receptors are located in the anterior part of the pump, and two groups of two B receptors are in the posterior part of the pump. Five sensory dendrites extend to the tip of each A receptor and four to each B receptors. Available evidence indicates that these receptors are contact chemoreceptors and do not serve as mechanoreceptors. The receptors are compared to those of other insects.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051600103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590301
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Changes in the fat body and oocysts during starvation and vitellogenesis in a mosquito, Aedes aegypti (L.)Scientific article number A2465 and contribution number 5495 of the Maryland Agricultural Experiment Station. (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 185-203 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: When Aedes aegypti females first emerge as adults, their oocytes possess no yolk. The abdominal fat body cells contain large quantities of lipid, protein, and glycogen, and possess many free ribosomes, but have very little rough endoplasmic reticulum (RER). When the females are starved for four days, their oocytes form fine lipid and protein yolk endogenously, the latter being located mainly around the nucleus. The adipocytes in these fasted mosquitoes have greatly reduced amounts of lipid, protein and glycogen and contain many cytolysosomes. Seven hours after 4-day-starved females had fed on blood, their oocytes begin filling with exogenous protein yolk at the oolemma, and lipid arises endogenously throughout the ooplasm. At this hour, the fat cells have synthesized more RER than is seen in unfed controls. Twenty-four hours post blood meal, the follicle cells have secreted discrete endochorionic plaques onto the oolemma. At this period, the adipocytes are densely filled with RER, and show for the first time many Golgi bodies and protein inclusions. They have noticeably less glycogen than at seven hours. Within 48 hours after mosquitoes have fed on blood, the endochorion forms a continuous layer around the steadily enlarging egg which is synthesizing additional protein and lipid yolk. Concurrently, the adipocytes show a greatly increased amount of glycogen and a significant reduction of RER. By the sixtieth hour after the blood meal, the follicle cells are attenuated, and the fat cells have less RER and more glycogen than at 48 hours. The nurse cells steadily decrease in size during vitellogenesis and release material onto the micropyle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    The timing of the onset of osteogenesis in the tibia of the embryonic chick (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 453-463 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Haematoxylin, Alcian Blue-Chlorantine Fast Red (ABCR) and the Ralis osteoid-specific stain were employed to closely follow the histogenesis of the tibia of the embryonic chick so as to provide an accurate description of the onset of ossification.An overview of the major cytological events preceding osteogenesis in the tibia was obtained from hindlimbs of embryos of H. H. (Hamburger and Hamilton, '51) stages 16-26 (2.5-5 days of incubation) stained with ABCR. A description of the cytological changes in the periosteum as it develops from the perichondrium and an analysis of the timing of the onset of osteoid deposition was obtained from the tibiae of accurately aged and staged embryos of H. H. stages 28-32 (5.5-8 days). These tibiae were stained specifically for the detection of osteoid:the freshly-secreted, unmineralized product of fully-differentiated osteoblasts. The perichondrium transformed into a bi-layered periosteum at H. H. late stage 29 (6.5 days) while osteoid was first detected adjacent to the hypertrophic cartilage of H. H. stage 30 (6.5-7 days) tibial diaphyses.These results, correlated with the immunoflourescent studies of Von der Mark et al. ('76a,b), which revealed the presence of Type I (bone-type) collagen-synthesizing cells in the perichondria of tibiae from embryos of H. H. stage 28 (5.5-6 days), demonstrated that the onset of determination of cells for osteogenesis and the cytodifferentiation of the periosteum are not temporally coupled.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620310
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Ultrastructure of the somatic portion of the gonads in asteroids, with emphasis on flagellated-collar cells and nutrient transportSupported by Sigma Xi Grant-in-Aid (Cornell University); Central University Research Fund and Hubbard Fund (University of New Hampshire) to C. W. Walker. (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 127-161 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Somatic portions of gonads in two phanerozonian sea-stars, Ctenodiscus crispatus and Hippasteria phrygiana, were similar in all aspects of gross structure and histology seen previously in both forcipulate and spinulosan asteroids. For the first time, detailed ultrastructural observations have been made of cells and tissues that reveal several features believed to be of universal occurrence in the gonads of asteroids. These include flagellated-collar cells in the visceral peritoneum and other coelomically derived epithelia, muscular-flagellated-collar cells in the visceral peritoneum and genital coelomic (perihaemal) sinus, the digestion of collagen fibers by cells in the connective tissue layer, and the intimate relationship of the genital haemal sinus and the entire germinal epithelium.Structural and functional compartmentalization are discussed in relation to major activities of the gonad throughout the annual reproductive cycle. The distinctive ultrastructure and current generation of flagellated-collar cells found in the visceral peritoneum are analyzed relative to their role in nutrient transport to gonadal tissues. The single flagellum of each flagellated-collar cell beats in coordination with those on neighboring cells to produce extremely rapid, oriented currents of coelomic fluid. The form of beating in an individual flagellum is planar, and the resulting synchronized activity of many adjacent flagella is non-metachronal; both of these characteristic aspects of current production have, thus far, been encountered together only in the Echinodermata. Flagellated-collar cells are efficient in generating currents which mix contents of the coelomic fluid, and they can presumably supply themselves with nutrients. It is concluded that nutrients so obtained are generally not passed through the wall of the gonad to the germinal epithelium and, as a result, have little to do with nutrition of somatic and germinal cells of the germinal epithelium. Alternatively, well-developed genital portions of the haemal system of the sea-star are advanced as the major channels supplying nutrients to germinal epithelia during gametogenesis.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    The structural organization of the pineal complex in the domestic goose (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 221-247 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The light and electron microscopic structure of the pineal complex of the domestic goose was studied. The complex is tubulofollicular but there is no direct connection between the constituent system of ducts and the third ventricle of the brain. Within the pineal, blood vessels accompanied by sympathetic nerve bundles are confined to the connective tissue. Other nerve fibers and occasional nerve cell bodies, however, do occur among the pineal cells.Three basic pineal cell types were distinguished: (1) elongate epithelial cells which are arranged around follicles and ducts and resemble degenerate photo-receptor cells; (2) intramural supportive cells which are interspersed with elongate epithelial and intramural supportive cells; and (3) small supportive cells which lie between the bases of the elongate epithelial and intramural supportive cells. The follicular structure, vascularization, presence of secretory granules, and the nature of the elongate epithelial cells indicate that the pineal complex is primarily endocrine though a possible photoreceptive function cannot be ignored. Vesicles, 100-300 and 40-100 nm wide, were found within nerves and intramural supportive cells. The larger vesicles, present in pineals collected in the night, probably contain peptidic hormones. The smaller vesicles present in both day and night samples probably contain aminergic hormones.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Nature and cellular origin of the adhesive coats of the lamprey egg (Petromyzon marinus)Supported by the Natural Sciences and Engineering Research Council of Canada, Grant A0657 to D. B. McMillan. (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 313-325 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cell surface coats are important in adhesion and other cellular activities. The lamprey egg possesses a surface coat that has been divided into two morphologically and functionally distinct regions. The amorphous apical tuft forms a cap over the animal pole, while the elaborately-textured adhesive coat covers the ventral two-thirds of the egg. This latter area is composed of saccules that form rosettes over the egg surface and is derived from the remains of specialized follicular cells which break down during ovulation. The adhesive qualities of these coats may be inhibited or abolished by various proteins and sulphydryl-blocking agents, thereby implicating, as a possible source of this adhesion, classes of acid and sulphated glycoproteins and glycosaminoglycans which occur on the egg surface.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    The wrist joint of two-toed sloths and its relevance to brachiating adaptations in the hominoidea (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 162 (1979), S. 413-424 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Two-toed sloths have evolved a wrist complex that includes the following traits: (1) diminution and distal migration of the pisiform, with a loss of contact with the ulna; (2) reduction of the distal end of the ulna to a styloid process; and (3) extremely reduced contact between the ulna and triquetrum. These traits were proposed by Lewis ('65, '74) to be indicative of brachiating habits and to be a unique adaptation of the Hominoidea. Cartmill and Milton ('77) recently found a similar complex in the wrists of the lorisines. Very similar adaptations of the wrist among the Hominoidea, lorisines, and two-toed sloths clearly refute contentions of Lewis and strengthen the hypothesis of Cartmill and Milton that the traits common to those animals are due to similar slow, cautious, but acrobatic locomotion.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051620308
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Effects of germanium on the morphology of silica deposition in a freshwater sponge (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 343-353 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effect of germanium on the secretion of siliceous spicules by the freshwater sponge Spongilla lacustris was investigated by exposing germinating and hatching gemmules to varying concentrations of germanium (Ge) in the presence of silicon (Si). Results were analyzed quantitatively and qualitatively and demonstrate that a [Ge]/[Si] (= molar ratio) of 1.0 completely inhibits silicon deposition. Intermediate ratios (0.5, 0.1, 0.01) which are permissive to spicule appearance result in fewer, shorter, and thinner spicules, in proportionately fewer microscleres, and in short bulbous megascleres. The size of the bulb increases with increasing [Ge]/[Si], while the length of the bulbous megascleres decreases with increasing [Ge]/[Si]. Microscleres do not demonstrate these graded responses suggesting that they are secreted in an all or none manner. Swellings produced in pond water and bulbs produced in germanium appear to decrease in size with time indicating a spreading of the accumulated silica. The effect of germanium on spicule secretion can be partially explained by its ability to uncouple the growth in length of the axial filament from the growth of the surrounding silicalemma. Under these conditions excess silicalemma is produced in which silica accumulates as bulbs in short spicules. Continuous exposure to Ge is necessary to produce this altered morphology. It is conjectured that the bulbs may be retained due to an inhibition of spreading. which in turn may be caused by the incorporation of germanium into the silica.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Partial regeneration of the above-elbow amputated rat forelimb. I. Innate responsesSupported by the Veterans Administration Medical Research Program, Project Number 7004-04 and a Medical Investigatorship Award to P.P. (1979)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 159 (1979), S. 427-437 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Although a number of recent studies describe the facilitation of limb regeneration by electrical and other forms of stimulation, little is known of innate regenerative capacity in the mammalian limb. The present report describes spontaneous regenerative responses following subtotal forelimb amputation in the young white rat. In one group of animals the forelimb was amputated through the lower humerus and the skin sutured closed. In a second group, adjacent muscle tissue still attached to bone at its origin(s) was interposed between the cut surface of the humerus and the skin. Among animals of the first group (skin closure only) bone growth and limb regenerative responses were generally not observed. Animals of the second group displayed significant elaborations of cartilage and bone at the limb terminus. The appearance and subsequent modification of these tissues suggest that some capacity for limb regeneration exists innately in the young rat and can be more readily evoked than has been recognized heretofore. It is concluded that extant and forthcoming reports of electrically stimulated skeletal tissue growth, repair and regeneration among eutherial mammals should be examined to determine whether reported responses to stimulation represent advances beyond what might be expected from innate replacement processes alone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051590308
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Elektrophile aromatische Substitutionsreaktionen mit protonierten 1,3-Diazinen, I. Darstellung und Eigenschaften 4-arylsubstituierter 3,4-Dihydropyrimidin-Derivate (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1-15 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electrophilic Aromatic Substitution Reactions with Protonated 1,3-Diazines, I. Preparation and Properties of 4-Aryl-substituted 3,4-Dihydropyrimidine DerivativesIn the presence of trifluoroacetic acid, pyrimidine and 5-methylpyrimidine react with active aromatic compounds to form stable 4-aryl-substituted 3,4-dihydropyrimidinium salts, e.g. 1, 2, 6. From these, the dihydro bases 7 or 8 can be obtained which are readily oxidized to 4-aryl-substituted pyrimidines 9. 2- and/or 4-substituted pyrimidines as well as 2-amino- and 2-mercaptopyrimidines react with phenols to form benz[g][1,3,5]oxadiazocines 3 and 10. The mechanism of this novel reaction is apparently best described as an aromatic electrophilic substitution by the protonated pyrimidine derivative. The observed reactivity of different diazines is in accordance with frontier orbital arguments, using HMO-coefficients.
    Notes: Bei Gegenwart von Trifluoressigsäure reagieren Pyrimidin und 5-Methylpyrimidin mit aktiven aromatischen Verbindungen zu stabilen 4-arylsubstituierten 3,4-Dihydropyrimidinium-Salzen, z. B. 1, 2, 6, aus denen sich die zugrunde liegende Dihydrobase 7 bzw. 8 erhalten läßt, die ihrerseits leicht zu 4-arylsubstituierten Pyrimidinen 9 oxidiert werden kann. 2- und/oder 4-substituierte Pyrimidine sowie 2-Amino- und 2-Mercaptopyrimidine bilden mit Phenolen Benz[g][1,3,5]oxadiazocine der (Konstitution 3a - f und 10. Als Reaktionsmechanismus wird eine elektrophile Substitutionsreaktion durch das protonierte Pyrimidinderivat vorgeschlagen. Die beobachtete Reaktivität der verschiedenen Diazine steht im Einklang mit dem Grenzorbital-Modell auf der Basis der HMO-Koeffizienten.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Umlagerungen freier Radikale, VII. Elektrocyclische und sigmatrope Umlagerungen des Bicyclo[3.1.0]hexenyl-Radikals (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 42-56 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangements of Free Radicals, VII. Electrocyclic and Sigmatropic Rearrangements of Bicyclo[3.1.0]hexenyl RadicalAbstraction of an allylic hydrogen from bicyclo[3.1.0]hex-2-ene (1) leads to the bicyclic allyl radical 2. Electrocyclic ring opening to the cyclohexadienyl radical 3 could not be observed in solution up to + 70°C. Only the product analysis of a thermolysis (130°C) of di-tert-butylperoxide in presence of 1 evidenced the possibility of ring opening with the formation benzene. In adamantane matrix 2 rearranges at -50°C in 3 (ΔG≠ = 68.6 ± 2.0 kJ/mol). In matrix bimolecular termination reactions are prohibited. Therefore rearrangements with activation barriers greater than those of diffusion controlled reactions can easily be observed. By this method a degenerate 1,4-sigmatropic rearrangement of the methylene bridge in 2 could be proven. For this purpose specifically in 2- and 3-position deuterated derivatives of 1 were synthesized. The sigmatropic reaction follows from the statistical distribution of deuterium in the cyclohexadienyl radical over the carbon atoms of the former five-membered ring.
    Notes: Durch Abstraktion eines allylischen Wasserstoffatoms aus Bicyclo[3.1.0]hex-2-en (1) läßt sich das bicyclische Allylradikal 2 erzeugen. Eine Ringöffnung zum Cyclohexadienylradikal 3 konnte in Lösung ESR-spektroskopisch bis + 70°C nicht beobachtet werden. Die Produktanalyse einer Thermolyse (130°C) von Di-tert-butylperoxid in Gegenwart von 1 erwies mit dem Auftreten von Benzol die grundsätzliche Möglichkeit zur elektrocyclischen Ringöffnung. In Adamantanmatrix lagert das durch Röntgenbestrahlung aus 1 erzeugte 2 bereits bei -50°C in 3 um (ΔG≠ = 68.6 ± 2.0 kj/mol). Die Matrixmethode macht durch die Unterdrückung bimolekularer Abreaktionen von 2 auch den Nachweis einer degenerierten sigmatropen 1,4- Verschiebung der Methylenbrücke möglich. Hierzu wurden in 2- bzw. 3-Stellung deuterierte Derivate von 1 dargestellt. Der Nachweis der sigmatropen Wanderung ergibt sich aus der statistischen Verteilung des Deuteriums im Cyclohexadienylradikal über die C-Atome. des ehemals fünfgliedrigen Ringes.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Protonenresonanz-Spektroskopie ungesättigter Ringsysteme, XXVII. Der Benzolkern als Sonde für die π-Elektronenstruktur von Annulenen; Teil IV: Dehydrobenzoannulene (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 71-83 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Proton Resonance Spectroscopy of Unsaturated Ring Systems, XXVII. The Benzene Nucleus as a Probe for the π-Electronic Structure of Annulenes; Part IV: DehydrobenzoannulenesThe 1H NMR Spectra of 6,9-dimethyl-7-monodehydrobenzo[12]annulene (1), 7,9-bisdehydrobenzo[14]annulene (2a), 6,11-dimethyl-7,9-bisdehydrobenzo[14]annulene (2a), 6,11-dimethyl-7,9-bisdehydrobenzo[16]annulene (3), and 9,11-bisdehydrobenzo[18]annulene (4) have been analyzed with respect to chemical shifts and H,H coupling constants. The electronic ground state properties of the annulene rings have been investigated using the Q-value method2). On the basis of the chemical shifts it was found that, compared to the free bisdehydroannulenes, the diatropic behaviour of 2a and 4 is reduced by ca. 70-80%, whereas the paratropic nature of 3 is diminished by less than 50%. Strong π-bond fixation exists in the annulene rings of 1-4.The conformations of the systems are discussed.
    Notes: Die 1H-NMR-Spektren von 6,9-Dimethyl-7-monodehydrobenzo[12]annulen (1), 7,9-Bisdehydrobenzo[14]annulen (2), 6,11-Dimethyl-7,9-bisdehydrobenzo[14]annulen (2a), 6,11-Dimethyl-7,9-bisdehydrobenzo[16]annulen (3) und 9,11-Bisdehydrobenzo[18]annulen (4) wurden hinsichtlich chemischer Verschiebungen und H,H-Kopplungskonstanten analysiert. Die elektronischen Eigenschaften des Grundzustandes der Annulenringe wurden mit Hilfe der Q-Wert-Methode2) untersucht. Aus den chemischen Verschiebungen wurde abgeleitet, daß das diatrope verhalten von 2a und 4 im Vergleich zu dem der freien Bisdehydroannulene um ca. 70-80% reduziert ist, während das paratrope Verhalten von 3 um weniger als 50% abgenommen hat. In den Annulenringen von 1-4 liegt eine starke π-Bindungsfixierung vor. Die Konformationen der Systeme werden diskutiert.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Darstellung und Molekülstruktur von μ-1,2-Dithiooxalato (S,S′)-bis[pentacarbonylmangan(I)] (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 95-98 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Molecular Structure of μ-1,2-Dithiooxalato(S S′)-bis [pentacarbonylamanganese(I)]The structure of the binuclear title compound 2 has been determined from X - ray data. 2 is formed by reaction of Cs2(OSC — CSO) with Mn(CO)5Br. The thiooxalato ligand has a transplanar conformation and connects the two Mn atoms through dative Mn — S — bonds.
    Notes: Die Struktur der zweikernigen Titelverbindung 2 wurde röntgendiffraktometrisch bestimmt. 2 entsteht durch Reaktion von Cs2(OSC — CSO) mit Mn(CO)5Br. Der Thiooxalato-Ligand besitzt transplanare Konformation und verknüpft über koordinative Mn— S — Bindungen die beiden Molekülhälften.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Über Aminosäuren und Peptide, XXVIII. Über Dehydroaminosäuren, XIV. Schiffsche Basen von Dehydroaminosäuren aus 2-Aryl-4-thiazolidincarbonsäuren.  -  Erste Synthese eines N-Aryliden-dehydroalaninesters (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 107-115 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Amino Acids and Peptides, XXVIII. On Dehydro Amino Acids, XIV. Schiff Bases of Dehydro Amino Acids from 2-Aryl-4-thiazolidinecarboxylic Acids.  -  First Synthesis of an N-Arylidene-dehydroalanine Esteron treatment with Ag2CO3 in aprotic solvents the 4-thiazolidinecarboxylic acid esters 1-4 afford the N-arylidene-dehydrovaline derivatives 5-8 in excellent yields. The dehydro peptides land 9 and 10 are obtained from the N-arylidene-dehydrovaline N-hydroxysuccinimide esters 7 and 8 by the reaction with amino acid amides. Methyl 2-phenyl-4-thiazolidinecarboxylate (12) reacts with Ag2CO3/DBU to yield the unstable N-benzylidene-aminoacrylic acid derivative 14, which On treatment with methanethiol yields the cysteine ester (RS)-13. Treatment of 12 with Ag2CO3/ CH3Br and without DBU-catalysis affords the optically active derivative (S)-13.
    Notes: Die 4-Thiazolidincarbonsäureester 1-4 reagieren mit Ag2CO3 in aprotischen Lösungsmitteln in ausgezeichneten Ausbeuten zu den N-Aryliden-dehydrovalin-Derivaten 5-8. Die N-Aryliden-dehydrovalin-N-hydroxysuccinimidester 7 und 8 können mit Aminosäureamiden zu den Dehydropeptiden 9 und 10 umgesetzt werden. 2-Phenyl-4-thiazolidincarbonsäure-methylester (12) bildet mit Ag2CO3 unter DBU-Katalyse den instabilen N-Benzyliden-aminoacrylsäureester 14, der mit Methanthiol zum Cysteinderivat (RS)-13 reagiert. Ohne DBU erhält man aus 12 mit Ag2CO3 und Methylbromid das optisch aktive (S)-13.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Syntheses of DL-Serine and of Precursors thereof (Glycolaldehyde and “Masked” Glycolaldehydes) (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 148-160 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesen von DL-Serin Vorläufern (Glycolaldehyd und „maskierte“ Glycolaldehyde)Bei Behandlung von Vinylchloridepoxid (4) mit Wasser, von Chlorethylencarbonat (9) mit wäßrigen Basen, von Vinylacetat (1) oder Ethylvinylether (6) mit wäßrigem Kaliumchlorat und einer katalytischen Menge Osmiumtetroxid bildete sich Glycolaldehyd (5) (Schema 1). Der nicht isolierte Aldehyd 5 lieferte bei der Zelinsky-Stadnikoff-Aminosäure-Synthese DL-Serin mit 70% Ausbeute. Diese Methode ergab, direkt von den „maskierten“ Glycolaldehyden 2, 7, 9, 10, Vinylencarbonat (11), 13 oder 14 ausgehend, ebenfalls DL-Serin (Ausbeuten 35-70%), wogegen ausgehend von 4 kein Serin nachgewiesen werden konnte.
    Notes: On treatment of vinyl chloride epoxide (4) with water, of chloroethylene carbonate (9) with aqueous bases, of vinyl acetate (1) or ethyl vinyl ether (6) with aqueous potassium chlorate and catalytic amounts of osmium tetroxide, glycolaldehyde (5) was formed (scheme 1). The not isolated aldehyde 5, when submitted to the Zelinsky-Stadnikoff amino acid synthesis, afforded DL-serine in 70% yield. The latter method, when applied directly to the “masked” glycolaldehydes 2, 7, 9, 10, vinylene carbonate (11), 13 or 14, also gave DL-serine (yields 35-70%), whereas with 4 no serine formation could be detected (scheme 1).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Die Umlagerung des 9-Cyan-cis-bicyclo[6.1.0]nona-2,4,6-trien-9-yl-Anions in das 9-Cyanbicyclo[4.2.1] nona-2,4,7-trien-9-yl-Anion Zur Frage der Bicycloaromatizität (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 175-195 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangement of the 9-Cyano-cis-bicyclo [6.1.0]nona-2,4,6-trien-9-yl Anion to the 9-Cyanobicyclo[4.2.1]nona-2,4,7-trien-9-yl Anion On the Problem of BicycloaromaticityReaction of methyl cis-bicyclo[6.1.0]nona-2,4,6-triene-9-anti-carboxylate (5b) with lithiumdiisopropylamide does not lead to deprotonation at C9 of 5b. Instead, a bridgehead cyclopropyl anion is formed which opens to give the allyl anion 12b.  -  In contrast, cis-bicyclo[6.1.0]nona-2,4,6-triene-9-anti-carbonitrile (5c) is also deprotonated at C9 leading to the 9-cyano-cis-bicyclo-[6.1.0]nona-2,4,6-trien-9-yl anion (1c), which rearranges comparatively fast (ΔG≠-43°C = 16.5 kcal · mol-1) to the 9-cyanobicyclo[4.2.1]nona-2,4,7-trien-9-yl anion (4c). Applying qualitative MO arguments of Goldstein and Hoffmann 4) one could explain the facile formation of the „bicyclo-aromatic“ 4c on the basis of ground state destabilization of 1c and stabilization of 4c. H/D-Exchange experiments, however, are at variance with this interpretation.  -  An additional stabilization of the transition state in the anionic sigmatropic rearrangement 1c → 4c as well as the opening the C1 — C9 bond instead of the central C1 — C8 bond are in agreement with HOMO-LUMO interactions.
    Notes: Die Umsetzung von cis-Bicyclo[6.I.0]nona-2,4,6-trien-9-anti-carbonsäure-methylester (5b) mit Lithiumdiisopropylamid führt nicht zu Deprotonierung an C9 von 5b. Statt dessen wird das Brückenkopfproton Hl abgespalten. Anionische Ringöffnung ergibt das Allyl-Anion 12b.  -  Im Gegensatz dazu wird das entsprechende 9-anti-Carbonitril 5c auch an C9 zum 9-Cyan-cis-bicyclo[6.1.0]nona-2,4,6-trien-9-yl-Anion (lc) deprotoniert, das vergleichsweise rasch (ΔG≠-43°C = 16.5 kcal · mo1) in das 9-Cyanbicyclo[4.2.1]nona-2,4,7-trien-9-yl-Anion (4c) umlagert. Qualitative MO-Überlegungen nach Goldstein und Hoffmann4) lassen vermuten, daß die leichte 1,5-Umlagerung auf Grundzustands-Destabilisierung von lc bzw. -Stabilisierung von 4c, mithin auf „Bicycloaromatizität“ von 4c, zurückzuführen ist. H/D-Austauschversuche zur Bestimmung von Anion-Stabilitäten stehen jedoch zu dieser Erklärung im Widerspruch.  -  Eine zusätzliche Stabilisierung des Übergangszustandes der anionischen sigmatropen Umlagerung 1c → 4c wie auch die seitliche statt der zentralen Bindungslösung im cyan-substituierten Anion 1c sind mit HOMO-LUMO-Wechselwirkungen zu verstehen.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120117
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Thieno[3,4-c]isothiazol. Synthese und Eigenschaften eines neuen nichtklassisch kondensierten Thiophens (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 260-265 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thieno[3,4-cisothiazole]. Synthesis and Properties of a New Nonclassical Condensed ThiopheneThe triphenylthieno[3,4-c]isothiazole 3 is a new 10 π heteroarene containing two different masked 1,3-dipolar systems. Its synthesis from 4-phenyl-1,3.2-oxathiazolylium-5-olate (1) and dibenzoyl-acetylene via the direct precursor 2 as well as its photoelectronic and electronic spectra are desribed. The observed electronic transitions of 3 are compared with the results of a PPP-CI calculation
    Notes: Das Triphenylthieno[3,4-c]isothiazol 3 ist ein neuer 10 π-Heteroaromat, der zwei verschiedene maskierte 1,3-dipolare Systeme beinhaltet. Seine Synthese aus 4-Phenyl-1,3,2-oxathiazolylium-5-olat (1) und Dibenzoylacetylen über die direkte Vorstufe 2 sowie sein Photoelektronen- und Elektronenspektrum werden beschrieben. Die an 3 beobachteten Elektronenübergänge werden mit den Ergebnissen einer PPP-CI-Rechnung verglichen.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120123
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Transanulare Wechselwirkungen bei [3.3]Phanen, III. [3.3]Paracyclophan, neue Synthesen, Sessel- und Wannen-Konformation (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 249-259 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transanular Interactions in [3.3]Phanes, III. [3.3]Paracyclophane, New Syntheses, Chair and Boat Conformation[3.3]Paracyclophane (1) was synthesized via the 2,13-dithia[4.4]paracyclophane (2) by vapor phase pyrolysis of the disulfone 3 obtained from 2. Reaction of 2 with benzyne gave trans- and cis-2,1 l-bis(phenylthio)[3.3]paracyclophane (4 and 5) by Stevens rearrangement. Oxidation to the sulfoxides 6 and 7 and pyrolysis yielded the [3.3]paracyclophanedienes (12/13) giving 1 on catalytic hydrogenation. Large substituents in the 2,11-positions of the bridges stabilize the two conformers of 1, based on 1H-NMR spectra the trans-isomer 4 has the chair, the cis-isomer 5 the boat conformation.
    Notes: [3.3]Paracyclophan (1) wurde über 2,13-Dithia[4.4]paracyclophan (2) durch Gasphasen-Pyrolyse des aus 2 erhaltenen Disulfons 3 synthetisiert. Reaktion von Dehydrobenzol mit 2 ergab durch Stevens-Umlagerung trans- und cis-2,11-Bis(phenylthio)[3.3]paracyclophan (4 und 5); durch Oxidation zu den Sulfoxiden 6 und 7 und Pyrolyse wurden die [3.3]Paracyclophandiene (12/13) erhalten, die bei katalytischer Hydrierung 1 ergaben. Große Substituenten in den 2,11-Positionen der Brücken stabilisieren die beiden Konformere von 1, laut 1H-NMR-Spektren liegt das trans-Isomere 4 in der Sessel-, das cis-Isomere 5 in der Wannen-Konformation vor.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120122
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Die Racemisierung spirocyclischer Pentaarylderivate von Elementen der V. Hauptgruppe, I. 1H-NMR-Untersuchungen mit sterisch überbesetzten asymmetrischen Phosphoranen, Arsoranen und Stiboranen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 281-291 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Racemization of Spirocyclic Pentaaryl Derivatives of Group 5 A Elements. I H NMR Investigations with Overcrowded Asymmetric Phosphoranes, Arsoranes, and StiboranesThe two different methyl positions of bis-2,2′-biarylylenephosphorane 7, the corresponding arsoranes 8a, b, and the analogous stiborane 9 are reversibly equilibrated at elevated temperatures with free enthalpies of activation of 18.2 (76.0), 17.2 (72.2), ≈ 22.5 (94.2), and 15.4 (64.6) kcal(kJ)/mol. Starting with the trigonal bipyramidal ground state conformations C and ∪ (fig. 2) these ligand exchange phenomena can be interpreted in the framework of the pseudorotation process on the basis of trigonal bipyramidal transition states of type A with diequatorial biarylylene groups.
    Notes: Die beiden unterschiedlichen Methyl-Positionen des Bis-2,2′-biarylylenphosphorans 7, der entsprechenden Arsorane 8a, b und des analogen Stiborans 9 werden bei erhöhten Temperaturen mit freien Aktivierungsenthalpien von 18.2 (76.0), 17.2 (72.2). ≈ 22.5 (94.2) und 15.4 (64.6) kcal(kJ)/mol reversibel äquilibriert. Ausgehend von den trigonal-bipyramidalen Grundzustandskonformationen C und ∪ (Abb. 2) lassen sich diese Ligandenaustauschphänomene im Rahmen des Pseudorotationsprozesses auf der Basis trigonal-bipyramidaler Übergangszustände des Typs A (Abb. 2) mit diäquatorialen Biarylylen-Gruppen interpretieren.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120125
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Lichtinduzierte Reaktionen, XIII. Über das seco-isomere Dienylketen aus 2,4-Androstadien-l-on (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 310-348 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Light-induced Reactions, XIII. On the Seco-isomeric Dienylketene Related to 2,4-Androstadien-1-oneThe steroidal 2.4-cyclohexadienone 3 photochemically affords the diastereomer 4. Both the configurational isomers differ exceedingly in their chiroptical properties. Their respective contribution to the photostationary state depends on the wave-length of the light and the solvent utilized. The dienylketene 5 can be determined spectroscopically as a transient. It is not trapped by 2,2,2-trifluoroethanol; cyclohexylamine, however, furnishes the 1,6-adduct 7a and/or the 1,2-adduct 6 a owing to the concentration and wave-length (365 or 313 nm) used.
    Notes: Das steroidale 2,4-Cyclohexadienon 3 geht photochemisch in das Diastereomere 4 über. Beide Konfigurationsisomere unterscheiden sich deutlich in ihren chiroptischen Eigenschaften. Ihr jeweiliger Anteil im photostationären Zustand hängt von der Wellenlänge des Lichts und dem Lösungsmittel ab. Das Dienylketen 5 läßt sich als Transient spektroskopisch nachweisen. Es wird von 2,2,2-Trifluorethanol nicht, von Cyclohexylamin je nach Konzentration und Wellenlänge (365 oder 313 nm) als 1,6-Addukt 7a und/oder als 1,2-Addukt 6a abgefangen.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120129
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Cyclisierungsprodukte aus N-arylsubstituierten Propiolamidinen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 384-388 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclic Substances from N-Aryl-substituted PropiolamidinesThe chloroformamidines 4a-c react with lithium phenylacetylide to form the propiolamidines 5a-c. 5a and 5b cyclize upon treatment with polyphosphoric acid to give the 2-aminoquinolines 6 and 7,8, respectively; 5c yields only the spiro compound 9.
    Notes: Die Chlorformamidine 4a-c reagieren mit Lithium-phenylacetylid zu den Propiolamidinen 5a-c. 5a bzw. 5b cyclisieren in Polyphosphorsäure (PPS) zu den 2-Aminochinolinen 6 bzw. 7 und 8, während 5c als einziges Produkt die Spiroverbindung 9 ergibt.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120134
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Konstitutionsaufklärung des Melochinins, eines Pyridon-Alkaloids neuen Typus aus Melochia pyramidata L. (Sterculiaceae) (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 376-383 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structure of Melochinine, a New Type of a Pyridone Alkaloid from Melochia pyramidata L. (Sterculiaceae)Melochinine, isolated from leafs of Melochia pyramidata L., is the first representative of a so far unknown class of pyridone alkaloids. Its structure was determined by spectroscopic methods in combination with microchemical degradation reactions to be 3.
    Notes: Das aus Melochia pyramidata L. isolierte Melochinin gehört einer bisher unbekannten Klasse von Pyridon-Alkaloiden an. Seine Struktur 3 wurde mit spektroskopischen Methoden und mikrochemischen Abbaureaktionen bestimmt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120133
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Photochemische Synthese von (η5-C5H5)2V2(CO)5 (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 392-393 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemical Synthesis of (η5-C5H5)2V2(Co)5μ-Dicarbonyl-tricarbonylbis[(η5-cyclopentadienyl)vanadium](V-V) (2) has been synthesized in 89% yield by photolysis of tetracarbonyl(η5 -cylcopentadienyl)vanadium (1) in tetrahydrofuran using a falling-film photoreactor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120136
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Masthead (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120201
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Natürlich vorkommende Terpen-Derivate, 156. Über eine neue Gruppe von Sesquiterpenlactonen aus der Gattung Trixis (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 435-444 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Naturally Occurring Terpene Derivatives, 156. On a New Group of Sesquiterpene Lactones from the Genus TrixisTwo species of the South American genus Trixis afforded 12 new sesquiterpenes all with a new pentacyclic ring system, named trixikingolide (3-8 and 10-24). The structures are elucidated by spectroscopic methods and chemical transformations which are in part unusual. The carbon skeleton is that of an isocedrene (1), first found in several other genera of the tribe Mutisieae. This type is probably of chemotaxonomical importance.
    Notes: Zwei Vertreter der südamerikanischen Gattung Trixi ergeben 12 neue Sesquiterpene, alle mit dem neuen pentacyclischen Ringsystem. das wir Trixikingolid genannt haben (3-8 und 19-24). Die Konstitutionen werden durch spektroskopische Methoden und chemische Umwandlungen, die zum Teil ungewöhnlich sind, geklärt. Das Kohlenstoffgerüst ist das eines Isocedrens (1), das zuerst in mehreren Gattungen der Tribus Mutisieae gefunden wurde. Dieser Typ ist wahrscheinlich von chemotaxonomischer Bedeutung.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Reaktionen von Azidocobalt(III)-Chelatkomplexen mit Isocyaniden (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 468-479 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Azidocobalt(III) Chelate Complexes with IsocyanidesAzidochelatecobalt(III) complexes N3Co(chelate)B (la-e) [chelate = e. g. dianion of N,N′-o-phenylenebis(salicylidenimine), B = PPh3] react with organic isocyanides to give metal-carbon bonded tetrazolate complexes 3, 4. 2-Isocyanoethanol affords tetrazolato- (9, 10) or azido-oxazolidin-2-ylidene complexes (11), depending on the nature of the solvent, the trans-base B, and the chelate ligand. The mechanism of formation of C-coordinated tetrazoles from azido complexes and isonitriles is discussed.
    Notes: Azidochelatcobalt(III)-Verbindungen N3Co(chelat)B(la-e) [chelat = z. B. Dianion von N,N′-o-Phenylenbis(salicylidenimin), B = PPh3] setzen sich mit organischen Isocyaniden zu Tetrazolatokomplexen 3, 4 mit Cobalt-Kohlenstoff-Bindung um. Mit 2-Isocyanethanol entstehen in Abhängigkeit vom Lösungsmittel, der trans-ständigen Base B und dem Chelatliganden Tetrazolato-(9, 10) oder Azido-oxazolidin-2-yliden-Komplexe (11). Der Mechanismus der Bildung C-koordinierter Tetrazole aus Azidokomplexen und Isonitrilen wird diskutiert.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120209
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Gold-Komplexe von Diphosphinomethanen, IV. AuI-Verbindungen von Diphosphinoaminen und oxidative Addition von Chlor zu AuII- und AuIII-Komplexen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 496-500 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Gold Complexes of Diphosphinomethanes, IV. Au1 Compounds of Diphosphinoamines and Oxidative Addition of Chlorine Yielding AuII and AuIII ComplexesBis(diphenylphosphino)amine (DPA) reacts with two equivalents of ClAu(CO) to form a binuclear gold complex HN[P(C6H5)2AuCl]2 (1). The analogous methylamine derivative (2) is prepared more easily from the ligand bis(diphenylphosphino)methylamine (DPMA) and HAuCl4 in ethanol. Excess DPMA. in the same solvent, yields a cyclic 1:1 complex 3 which is electrolytically dissociated in acetonitrile. 2 can be oxidized using stoichiometric amounts of chlorine to form complexes with the formal oxidation states +2 (5) and +3 (6) of gold. l97Au Mößbauer spectra prove that 5 is indeed not a mixed Au1/AuIII compound but contains the structural moiety Au24⊕.  -  DPA can be metallated at the nitrogen with n-C4H9Li and transformed into [(C6H5)2P]2NSI(CH3)3 using (CH3)3SiCi, but no gold complex was obtained from this ligand.
    Notes: Bis(diphenylphosphino)amin (DPA) reagiert mit zwei Äquivalenten ClAu(CO) zum zweikernigen Goldkomplex HN[P(C6H5)2AuCl]2 (1). Das analoge Methylaminderivat (2) kann leichter aus dem Liganden Bis(diphenylphosphino)methylamin (DPMA) und HAuCl4 in Ethanol erhalten werden. Überschüssiges DPMA ergibt im gleichen Solvens den cyclischen 1 : 1-Komplex 3, der in Acetonitril elektrolytisch dissoziiert. 2 kann mit stöchiometrischen Mengen Chlor in Komplexe übergeführt werden, in denen Gold formal die Oxidationsstufen +2 (5) und +3 (6) besitzt. 197Au-Mößbauer-Spektren beweisen, daß 5 tatsächlich keine gemischte AuI/AuIII 1-Verbindung ist, sondern das Strukturelement Au24⊕ enthalten muß.  -  DPA kann mit n-C4H9Li am Stickstoff metalliert und mit (CH3)3SiCl in den Liganden [(C6H5)2P]2NSi(CH3)3 verwandelt werden, von dem jedoch noch kein Goldkomplex zu erhalten war.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120212
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Oxiran- und Oxetanspaltung mit Phosphor-Yliden: Ein Weg zu mono- und spirobicyclischen Phosphoranen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 501-509 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxirane and Oxetane Cleavage with Phosphorus Ylides: A Pathway to Fluctuating Mono- and Spirobicyclic Phosphoranes1-Methyl-1-methylen-1 λ5-phospholane (1) and -phosphorinane (3) react with oxirane under mild conditions to form the spirobicyclic phosphoranes 2 and 4, resp., in high yields. Oxetane converts the same ylides into the corresponding heterocycles 6 and 7 only at elevated temperatures and under autogenic pressure in sealed tubes. Similarly, trimethylmethylenephosphorane inserts into oxetane with formation of the monocyclic 2,2,2-trimethyl-1,2λ5-oxaphosphorinane (5).  -  A detailed variable temperature NMR study leads to trigonal bipyramidal ground state geometries of the phosphoranes 2 and 4-7. Their fluctuating behaviour, for which any irregular process could be excluded, is most easily described by the turnstile model of pseudorotation. The compounds reported appear to be the most simple cyclic systems of the type R4POR′ available to date.
    Notes: 1-Methyl-1-methylen-1λ5-phospholan (1) und -phosphorinan (3) reagieren schon unter milden Bedingungen mit Oxiran in guten Ausbeuten zu den spirobicyclischen Phosphoranen 2 bzw. 4. Oxetan verwandelt die gleichen Ylide in die entsprechenden Heterocyclen 6 und 7, jedoch erst bei höherer Temperatur und unter Eigendruck im Bombenrohr. Trimethylmethylenphosphoran wird in ähnlicher Weise in den Oxetanring eingeschoben, wobei das monocyclische 2,2,2-Tri-methyl-1,2Δ5-oxaphosphorinan(5)entsteht.  -  Ein detailliertes Studium der temperaturabhängigen NMR-Spektren führte zu einer trigonal-bipyramidalen Grundzustandsgeometrie der neuen Phosphorane 2 und 4-7. Deren fluktuierendes Verhalten, für das irreguläre Prozesse ausgeschlossen werden konnten, ist am leichtesten unter Zuhilfenahme des Turnstile-Modells zu beschreiben.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120213
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Polycyclische Verbindungen, XII. Vicinale cis-trans-isomere Dihydrodiole in der Hexahydrophenanthren- und -benz[a]anthracen-Reihe (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 532-540 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polycyclic Compounds, XII. Vicinal cis-trans-Isomeric Dihydrodiols in the Hexahydrophenanthrene and -benz[a]anthracene SeriesThe synthesis of the Vicinal trans-dihydrodiols 3a and 1la in the hexahydrophenanthrene and -benz[a]anthracene series is described. 3a and 1la are obtained by reaction of the oxanorbornadienes 1 and 9 with acetic acid and subsequent alkaline hydrolysis of the trans-hydroxyacetates 3b and 11b. Specific reactions of the cis-trans-isomers 2a and 3a are described.
    Notes: Die Darstellung der vicinalen trans-Dihydrodiole 3a und 11a in der Hexahydrophenanthren-und -benz[a]anthracen-Reihe wird beschrieben. 3a und 11a erhält man durch Reaktion der Oxanorbornadiene 1 und 9 mit Essigsäure und anschließende alkalische Verseifung der trans-Hydroxyacetate 3b und l1b. Spezifische Reaktionen der cis-trans-Isomeren 2a und 3a werden besprochen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120216
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Enantiomere Pentatetraene und deren thermische Racemisierungsbarrieren (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 567-576 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enantiomeric Pentatetraenes and their Thermic Racemization EnergiesPartial hydroboration of the racemic pentatetraene 4 with chiral di(3-pinanyl)borane (6) gives the olefins 7 and 8, and starting material with about 5% enrichment of one enantiomer of 4. Complete separation of the enantiomers of 4 is achieved by chromatography on microcrystalline peracetylated cellulose. ( + )-4 with [α]D22 = + 336.6° (c = 0.8; CHC1,3) most likely has (S)-configuration. The enantiomers 4 racemize thermally at 358 K with activation parameters of ΔH≠ = 109.4 ± 1 kJmol-1, ΔS≠ = -18 ± 5JK-1 mol-1. and ΔG≠ = 115.8 ± 0.1 kJmol-1, independent of the polarity of the solvent.
    Notes: Die partielle Hydroborierung des racemischen Pentatetraens 4 mit chiralem Di(3-pinanyl)boran (6) führt zu den Olefinen 7 und 8, wobei im zurückgewonnenen Ausgangsmaterial 5% eines Enantiomeren von 4 angereichert werden. Die vollständige Enantiomerentrennung von 4 gelingt durch Chromatographie an mikrokristalliner peracetylierter Cellulose. (+)-4, [α]D22 = + 336.6° (c = 0.8; CHC13), besitzt wahrscheinlich (S)-Konfiguration. Die thermische Racemisierung von 4 ist bei 358 K von der Polarität des Mediums unabhängig und ergibt ΔH≠ = 109.4 ± l kJmoI-1, ΔS≠ = -18 ± 5JK-1mol-1 und ΔG≠ = 115.8 ± 0.1 kJmol-1.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120220
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Tautomerie von Heterocyclen, VII. Synthese und Reaktionen N-vinylsubstituierter Chlorformamidine (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 640-647 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tautomerism of Heterocyclic Compounds, VII. Synthesis and Reactions of N-Vinylsubstituted ChloroformamidinesThe ureas 1 a, b are converted into the N-vinylsubstituted chloroformamidines 2 a, b by using triphenylphosphane/carbon tetrachloride as chlorinating agent. They react with silver cyanate potassium thiocyanate, potassium selenocyanate, 4-morpholinecarbonitrile and lithium phenyl-acetylide to form the substituted heterocyclic compounds 3 a, b, 5 a, b-7 a, b, 9 a, b, and 12.
    Notes: Die Harnstoffe 1 a, b werden mit Hilfe des Chlorierungsreagenzes Triphenylphosphan/Tetrachlorkohlenstoff in N-vinylsubstituierte Chlorformamidine 2 a, b übergeführt. Ihre Umsetzung mit Silbercyanat, Kaliumthiocyanat, Kaliumselenocyanat, 4-Morpholincarbonitril und Lithiumphenylacetylid liefert die substituierten Heterocyclen 3a, b, 5a, b-7a, b, 9a, b und 12.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120225
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Borierungsreaktionen am Keten (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 654-662 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Boration Reactions of KeteneTwo series of products are formed by aminoboration of ketene with R2B—NMe2: BR3 and CH3CONMe2, derived from a primary CC-aminoboration product R2B—CH2 —CONMe2, and the oxaazoniaboratacyclohexanes 3 and 4, derived from a primary CO-aminoboration product CH2 = C(NMe2)—OBR2. The aminoboration of ketene with HalB(NR2)2 leads to [(R2N)HalB—CH2-CONR2]2 (6). The bromoboration of ketene with Me2B—Br yields intermediates which, by aminolysis. can be transformed into products similar to those of direct aminoboration.
    Notes: Die Aminoborierung von Keten mit R2B—NMe2 liefert nebeneinander die Produkte BR3 und CH3 CONMe2, die sich vom CC-Aminoborierungsprodukt R2B—CH2—CONMe2 herleiten, sowie die Oxaazoniaboratacyclohexan-Derivate 3 und 4. die sich aus dem CO-Aminoborierungsprodukt CH2 = C(NMe2)—OBR2 bilden. Die Aminoborierung von Keten mit HalB(NR2)2 ergibt [(R2N)HalB—CH2—CONR2]2 (6). Bei der Bromoborierung von Keten mit Me2B—Br kommt man zu instabilen Zwischenprodukten. deren Aminolyse zu ähnlichen Produkten führt wie die Aminoborierung von Keten mit Me2B—NR2.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120227
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Darstellung und Eigenschaften von (2-Methyl-1-propenyloxy)-boranen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 663-677 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Properties of (2-Methyl-1-propenyloxy)boranes(2-Methyl-1-propenyloxy)boranes Me2C = CY—OBXX′ (2a-o) with different groups X, X′, and Y were prepared either by the addition of boranes XX′BY to dimethylketene Me2C = C = O or by the transfer of a Me2CCYO group from BrZn(Me2CCYO) to bromoboranes XX′BBr. The products dissociate thermally into XX′BY and Me2C = C = O. No tautomerism yielding XX′B—CMe2—CY = O was observed. Addition of ketene H2C = C = O to a few of the compounds 2 and subsequent methanolysis give H3C—CO—CMe2—CO2Me. The products O = CBr—CMe2—CHR—OBMe2 can be isolated from the addition of Me2C = CBr—OBMe2 (2a) to aldehydes RCHO.
    Notes: (2-Methyl-1-propenyloxy)borane Me2C = CY—OBXX′ (2a-o) mit verschiedenen Gruppen X, X′ und Y wurden z. T. durch Addition von Boranen XX′BY an Dimethylketen Me2C = C = O, z. T. durch Übertragung des Me2CCYO-Rests von BrZn(Me2CCYO) auf Bromborane XX′BBr dargestellt. Die thermische Spaltung führt zu XX′BY und Me2C = C = O. Eine die Produkte XX′B—CMe2—CY = O ergebende Tautomerie haben wir nicht beobachtet. Die 1:1-Umsetzung einiger der Produkte 2 mit Keten H2C = C = O und die nachfolgende Methanolyse der Addukte liefern den Ester H3C—CO—CMe2—CO2Me. Durch Addition von Aldehyden RCHO an Me2C = CBr—OBMe2 (2a) gewinnt man die Produkte O = CBr—CMe2 —CHR—OBMe2.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120228
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    3-Desamino- und 3-Descarboxyderivate des Nucleosids „X“ (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 700-707 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 3-Deamino- and 3-Decarboxy-Derivatives of the Nucleoside „X“Since biosynthetic investigations have shown that the aminocarboxypropyl side chain of the nucleoside „X“ (la) comes from S-adenosyl-L-methionine (2) and that compound 2 can also function as a donor of methyl-, aminopropyl- and carboxypropyl-groups, we have synthesized the two unknown uridine derivatives l b and l c. The latter compounds were obtained via N -3-alkylation of 2′,3′-O-isopropylideneuridine followed by removal of the protecting groups and characterized by 13C NMR spectroscopy. In contrast to the UV spectra the 1 H NMR spectra of 1a - c show a strong dependence on pH.
    Notes: Da Biosyntheseuntersuchungen gezeigt haben, daß der Aminocarboxypropylrest des Nucleosids „X“ (la) von S-Adenosyl-L-methionin (2) stammt, 2 aber auch als Donor von Methyl-, Aminopropyl- und Carboxypropylresten fungieren kann, haben wir die beiden noch unbekannten Uridinderivate 1 b und 1 c über N-3-Alkylierung von 2′,3′-O-Isopropylidenuridin und anschließende Abspaltung der Schutzgruppen dargestellt. l a - c wurden durch 13C-NMR-Spektroskopie charakterisiert. Im Gegensatz zu den UV-Spektren zeigen die 1 H-NMR-Spektren dieser Verbindungen eine starke Abhängigkeit vom pH-Wert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120231
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Pentacarbonyl{furyl[tris(trimethylsilyl)siloxy]carben}chrom(0): Ein Carben-Komplex mit bemerkenswerten chemischen und strukturellen Eigenschaften (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 708-716 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pentacarbonyl{furyl[tris(trimethylsilyl)siloxy]carbene}chromium(0): A Carbene Complex with Remarkable Chemical and Structural PropertiesThe title compound 4 reacts with an ethereal solution of lithium bromide by cleavage of the Si—O bond. 13C and 29Si NMR spectroscopic investigations as well as an X-ray structure determination show the central Si atom of 4 to have a distorted trigonal-bipyramidal configuration by interaction with the oxygen atom of the furyl moiety both in solution and in crystalline state. The Si—O bond within the carbene ligand is strongly lengthened.
    Notes: Die Titelverbindung 4 reagiert mit etherischer Lithiumbromid-Lösung unter Spaltung der Si—O—Bindung. 13 C- und 29Si-NMR-spektroskopische Untersuchungen sowie eine Röntgenstrukturanalyse zeigen, daß sowohl in Lösung als auch im festen Zustand das zentrale Silicium-Atom von 4 durch Wechselwirkung mit dem Sauerstoff-Atom des Furyl-Restes eine verzerrt trigonal-bipyramidale Konfiguration aufweist. Die Si—O—Bindung im Carben-Liganden ist stark aufgeweitet.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120232
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Synthesen biologisch wichtiger Kohlenhydrate, 16. Stereoselektive Synthese der 3-Dimethylamino-2,3,6-tridesoxy-ribo-hexose (DL-Megosamin) (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 717-726 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Biologically Important Carbohydrates, 16. Stereoselective Synthesis of 3-Dimethylamino-2,3,6-trideoxy-ribo-hexose (DL-Megosamine)Methyl trans-4,5-epoxy-2,3,6-trideoxy-DL-threo-hex-2-enonate (1) reacts with liquid dimethylamine at - 10°C in nearly quantitative yield with formation of the 3-dimethylamino-4,5-epoxy-2,3,6-trideoxy-DL-lyxo-/xylo-hexonates 8. Epimeric 8 is transformed in one step into the corresponding 3-dimethylamino-γ-lactone hydrochlorides 10 from which the ribo-isomer is obtained by fractional crystallization. The highly critical reduction of 10 which represents a β-dialkylaminolactone is possible with good success if diisobutylaluminium hydride (DIBAH) is used under controlled conditions. The 3-dimethylamino-2,3,6-trideoxy-DL-ribo-hexopyranose (11) is very instable. Its configuration is established by the MS- and 1H-NMR-spectra of the much more stable 1,4-di-O-acetyl derivative 12 L-11 (megosamine) is known as one of the sugar components of the megalomicin antibiotics 27.  -  This four step synthesis of DL-12 gives a total yield of 29%.
    Notes: trans-4,5-Epoxy-2,3,6-tridesoxy-DL-threo-hex-2-enonsäure-methylester (1) reagiert mit flüssigem Dimethylamin bei -10°C fast quantitativ zu den epimeren 3-Dimethylamino-4,5-epoxy-2,3,6-tridesoxy-DL-lyxo-/-xylo-hexonsäureestern 8, die in einem Schritt zu den entsprechenden 3-Dimethylamino-γ-lacton-hydrochloriden 10, umgesetzt werden. Von diesen wird das ribo-Isomere durch fraktionierende Kristallisation erhalten. Die sehr kritische Reduktion von 10, einem β-Dialkylamino-lacton gelingt glatt, wenn man mit Diisobutylaluminiumhydrid (DIBAH) unter kontrollierten Bedingungen arbeitet. Die Konstitution und Konfiguration der sehr empfindlichen 3-Dimethylamino-2,3,6-tridesoxy-DL-ribo-hexopyranose (11) werden durch MS- und 1H-NMR-Untersuchungen an dem wesentlich stabileren 1,4-Di-O-acetyl-Derivat 12 bestimmt. L-11 ist als Baustein Megosamin von Macrolid-Antibiotika27) von Interesse.  -  Die Ausbeute an DL-12 beträgt 29% über alle vier Stufen.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120233
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Feldionenkinetik der Wassereliminierung aus den Molekül-Ionen stereoisomerer Decalin-1,4-diole (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 743-762 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Field Ion Kinetics of the Water Elimination form Molecular Ions of Stereoisomeric Decalin-1,4-diolsThe field ion kinetics (FIK) of the elimination of H2O from the molecular ions of the 6 stereoisomeric decalin-1,4-diols, of 6 stereoisomers of 2-methyldecalin- 1,4-diol, and of 3 stereoisomers of 9-methyl-trans-decalin-1,4-diol has been investigated for reaction times between 5.10-11 and 5.10-9s. Characteristic FIK-curves of normalized intensities If(t/Im of the [M — H2O]+· ions have been obtained for all compounds. The structure of the curves is mainly determined by the relative steric orientation of both hydroxy groups, in compounds with a 1,4-cis-orientation of the hydroxy groups also by the geometry of other parts of the molecules. Methyl groups, however, have no noticeable effect on the structure of the curves. The investigation of specifically deuterated derivatives reveals, that the intensity curves of the [M —H2O]+· ions are the result of a superposition of at least 4 elimination reaction: 1.) A rapid loss of water by 1,2-elimination. 2) A retarded 1,5-elimination by a reaction between hydroxy groups in a 1,4-cis-position. 3) A retarded transannular 1,4-elimination in compounds with a 1,4-trans-orientation of the hydroxy group. 4.) A retarded loss of water by H-transfer from the unsubstituted ring to one of the hydroxy groups. The retardation of the loss of water is discussed with respect to intramolecular movements of the molecular ions.
    Notes: Die Feldionenkinetik (FIK) der Wasserabspaltung aus der Molekül-Ionen der 6 stereoisomeren Decalin-1,4-diole, von 6 Stereoisomeren des 2-Methyldecalin-1,4-diols und von 3 Stereoisomeren des 9-Methyl-trans-decalin- 1,4-diols wurde Für Zerfallszeiten von 5. 10-11 bis 5. 10-9s unter-sucht. Für die normalisierten Intensitäten If(t)/IM der Ionen [M — H2O]+· wurden für alle Verbindungen charakteristische FIK-Kurven erhalten. Der Kurvenverlauf wird vorwiegend durch die relative sterische Anordnung beider Hydroxygruppen bestimmt, bei Verbindungen mit 1,4-cis-ständigen Hydroxygruppen auch durch die übrige Molekulargeometrie. Methylsubstituenten machen sich dagegen nicht im Kurvenverlauf bemerkbar. Durch Untersuchung spezifisch deuterierter Derivate wird gezeigt, daß die Intensitätskurven der [M — H2O]+·-Ionen durch eine Überlagerung von mindestens 4 Eliminierungsprozessen entstehen: 1. Eine schnelle Wasserabspaltung durch 1,2-Eliminierung. 2.Eine zeitlich verzögerte 1,5-Eliminierung durch Reaktion zwischen 1,4-cis-ständigen Hydroxygruppen. Eine zeitlich verzögerte transannulare 1,4-Eliminierung bei Verbindungen mit 1,4-trans-ständigen Hydroxygruppen. 4. Eine zeitlich verzögerte Wasserabsplatung durch H-Übertragung aus dem unsubstituierten Ring auf eine der Hydroxygruppen. Die zeitliche Verzögerung der Wasserabsplatung wird im Zusammenhang mit intramolekularen Bewegungen der Molekül-Ionen diskutiert.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120236
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Eine einfache Darstellung der binären Metall-Schwefel-Cluster [Mo3S13]2- und [Mo2S12]2- aus MoO4 2- in praktisch quantitativer Ausbeute (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 778-780 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Simple Preparation of the Binary Metal-Sulfur Clusters [MO3S13]2- and [Mo2SI2]2- from MoO42- in Practically Quantitative Yield(NH4)2[Mo3S(S2)6] 2 H2O (2) could be isolated by heating an aqueous solution of MoO42- with (NH4 2- Sx, for several hours. The anions of both compounds are in equilibrium under the stated conditions.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120240
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Ambivalentes Verhalten von Acyl(diphenyl)phosphanen gegenüber molekularem Sauerstoff (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 793-798 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ambivalent Behavior of Acyl(diphenyl)phosphanes towards Molecular OxygenWhen the acylphosphanes RC(O)PPh2 (4a, b) [R = CH3 (a), CF3 (b)] are „oxidized slowly“ with molecular oxygen the trivalent phosphorus is attacked with formation of the phosphane oxides RC(O)P(O)Ph2 (la, b), which react with water to give the alcohols RC[Ph2P(O)]2OX(2)and phosphinates RC[Ph2P(O)][OP(O)Ph2]X (3). In contrast, „fast oxidation“ results in an attack on the carbonyl group of 4a b, with formation of CO2 and the radicals ·PPh2 and ·R. The combination products of these radicals and the capture reaction with water and alcohols are described.
    Notes: Bei der „langsamen Oxidation“ der Acylphosphane RC(O)PPh2 (4a, b) [R = CH3 (a), CF3, (b)] mit molekularem Sauerstoff wird der dreibindige Phosphor unter Bildung der Phosphanoxide RC(O)P(O)Ph2 (l a, b) angegriffen, welche mit Wasser zu den Alkoholen RC[Ph2P(O)]2OX (2) und Phosphinaten RC[Ph2P(O)][OP(O)Ph2]X (3) weiterreagieren. Im Gegensatz hierzu erfolgt bei der „schnellen Oxidation“ der Angriff des Sauerstoffs an der Carbonylgruppe von 4a, b unter Bildung von CO2 und der Radikale · PPh2 und · R. Die Kombinationsprodukte dieser Radikale und die Abfangreaktion mit Wasser und Alkoholen werden beschrieben.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Anodische Hydroxylierung und Acetamidierung von konjugierten Dienen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 807-817 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Anodic Hydroxylation and Acetamidation of Conjugated DienesAnodic oxidation of 2,4-hexadiene (1), 1,3-butadiene (2), and 1,3-cyclohexadiene (3) in acetonitrile water/sodium perchlorate yields diols, 2-oxazolines, and 3-pyrrolines. Methyl sorbate (5) forms methyl 4,5-epoxy-(E)-2-hexenoate (26); 1,4-diphenyl-1,3-butadiene (4) is cleaved to benzaldehyde (24) and cinnamaldehyde (25). The product distribution is influenced by the supporting electrolyte. With tetrafluoroborate nearly exclusively diols are obtained, whilst in acetamide/acetonitrile 2-oxazolines and 3-pyrrolines are formed. As intermediates radical cations (31) are assumed.
    Notes: Die anodische Oxidation von 2,4-Hexadien (1), 1,3-Butadien (2) und 1,3-Cyclohexadien (3) in Acetonitril/Wasser/Natriumperchlorat führt zu einem Gemisch aus Diolen, 2-Oxazolinen und 3-Pyrrolinen. Sorbinsäure-methylester (5) liefert 4,5-Epoxy-(E)-2-hexensäure-methylester (26); 1,4-Diphenyl-1,3-butadien (4) wird zu Benzaldehyd (24) und Zimtaldehyd (25) gespalten. Die Produktverhältnisse werden vom Leitsalz beeinflußt. In Gegenwart von Tetrafluoroborat entstehen nahezu ausschließlich Diole, während die Elektrolyse in Acetamid/Acetonitril zu 2-Oxazolinen und 3-Pyrrolinen führt. Als Zwischenprodukte werden Radikalkationen (31) angenommen.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Synthesen und Reaktionen von L-Olivomycal und L-Mycaral (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 818-822 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reaction of L-Olivomycal and L-MycaralStarting with L-rhamnal (3) the synthesis of L-olivomycal (4a) is achieved with only few steps and in high yields. Following hydrogenation of 4a and the isomeric side product L-mycaral (5), to the corresponding 1,5-anhydro derivatives 7 and 8, only 8 gave a cis-carbonate 9. This proves the configuration at the branching point C-3 in 4a and in 5. By the reaction of 4b with methanol and N-iodosuccinimide 10b is obtained, which, after subsequent reduction employing nickel boride, gave methyl α-L-olivomycoside (11) in high yield. By application of the same procedure the disaccharide derivative 13 is synthesized without problems.
    Notes: Die Synthese von L-Olivomycal (4a) gelingt in wenigen Reaktionsschritten und guten Ausbeuten ausgehend von L-Rhamnal (3). Nach Hydrierung von 4a und dem isomeren Nebenprodukt L-Mycaral (5) zu den entsprechenden 1,5-Anhydroverbindungen 7 und 8 reagiert nur 8 zu einem cis-Carbonat 9, womit die Konfiguration am Verzweigungspunkt C-3 in 4a und 5 belegt wird. Umsetzung von 4b mit Methanol und N-Iodsuccnimid zu 10b und nachfolgende Reduktion mit Nickelborid gibt Methyl-α-L-olivomycosid (11) in hoher Ausbeute. Gleichermaßen gelingt die glatte Synthese des Disaccharidderivats 13.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Kristallstrukturen der Alkali-isopropoxide des Kaliums, Rubidiums und Caesiums (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 844-848 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structures of the Isopropoxides of Potassium, Rubidium, and CesiumPotassium-, rubidium- and cesium isopropoxide are isostructural (tetragonal space group P4/nmm-D4h7). Their cell constants have been determined. Using a single crystal the structure of cesium isopropoxide has been determined by X-ray analysis and refined to R = 0.069. The alkoxides form layer structures of the type of lithium respectively sodium methoxide. The metal atoms are arranged in one plane and are coordinated on both sides by O-atoms. each O-atom being surrounded by four metal atoms and one sec. C-atom. The methyl-C-atoms are distributed statistically between two positions differing by a 90° rotation of the (CH3)2CH-group.
    Notes: Die Isopropoxide des Kaliums, Rubidiums und Caesiums sind isostrukturell tetragonale Raum-gruppe P4/nmm-D4h7). Ihre Zellkonstanten wurden ermittelt und die Struktur des Caesium-isopropoxids anhand eines Einkristalls röntgenographisch bestimmt und bis R = 0.069 verfeinert. Die Alkoxide bilden Schichtgitter vom Typ des Lithium- bzw. Natriummethoxids. Dabei liegen die Metallatome in einer Ebene und sind beiderseits von O-Atomen koordiniert, indem jedes O-Atom von vier Metallatomen und einem sec. C-Atom umgeben ist. Die Methyl-C-Atome sind statistisch auf zwei Lagen verteilt, welche sich durch Drehung der (CH3)2CH-Gruppe um 90° unterscheiden.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120309
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Basische Metalle, X. C5H5Co(PMe3)2 als Synthesebaustein zur Knüpfung von Metall-Metall-Bindungen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 823-833 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Basic Metals, X. C5H5Co(PMe3)2 as Building Block for the Formation of Metal-Metal BondsC5H5Co(PMe3)2 (1) reacts with equimolar amounts of ZnCl2 and PMe3 to give the complex C5H5(PMe3)2CoZnCl2(PMe3)(2). Contrary, 1, ZnCl2 and PPh3 react to give a mixture of C5H5(PMe3)2CoZnCl2 (3) and (PPh3)2ZnCl2. The reaction of 2 with PMe3 leads to cleavage of the Co—Zn bond with formation of 1 and (PMe3)2ZnCl2. - 1 reacts with [(PMe3)2CuCl]2 to give C5H5(PMe3)2CoCuCl(PMe3)2(4). In this complex and in 2, the metal atoms are probably tetrahedrally coordinated. Reaction of 4 with PMe3 leads to 1 and (PMe3)3CuCl. - Complexes having Co—Sn bonds can be synthesized through reaction of 1 with SnCl4. Me3SnCl. and Ph3SnCl. The 1:1 adducts 5, 8, and 9 that are first formed react with SnCl4 or NH4PF6 with loss of a chloride ion and formation of the cationic complexes [C5H5(PMe3)2CoSnR3]+ (R = Cl, Me, Ph) (6, 11 and 12). Electrophilic substitution of the SnMe3 group in [C5H5(PMe3)2CoSnMe3]PF6 (11) by SnCl4 or HgCl2 leads to [C5H5(PMe3)2CoSnCl3]PF6 (10) or [C5H5(PMe3)2CoHgCl]PF6 (14), respectively. - With HgCl3 1 forms both a 1:1 and a 1 :2 adduct (13 and 15). Structural suggestions for these compounds are discussed.
    Notes: C5H5Co(PMe3)2 (1) reagiert mit äquimolaren Mengen ZnCl2 und PMe3 zu dem Komplex C5H5(PMe3)2CoZnCl2(PMe3)(2). Aus 1, ZnCl2 und PPh3 entsteht dagegen ein Gemisch von C5H5 (PMe3)2CoZnCl2 (3) und (PPh3)2ZnCl2. Die Reaktion von 2 mit PMe3 führt unter Spaltung der Co—Zn-Bindung zu 1 und (PMe3)2ZnCl2. - Mit [(PMe3)2CuCl]2 reagiert 1 zu C5H5(PMe3)2CoCuCl(PMe3)2(4), in dem wahrscheinlich wie in 2 beide Metallatome tetraedrisch koordiniert sind. Bei der Umsetzung von 4 mit PMe3 bildet sich 1 und (PMe3)3CuCl. - Die Synthese von Komplexen mit Co—Sn-Bindungen gelingt durch Reaktion von 1 mit SnCl4, Me3SnCl und Ph3SnCl. Die primär gebildeten l : l-Addukte 5, 8 und 9 reagieren mit SnCl4 bzw. NH4PF6 unter Abspaltung eines Chlorid-Ions und Bildung der kationischen Komplexe [C5H5(PMe3)2CoSnR3]+(R = Cl, Me, Ph) (6, 11 und 12). Die elektrophile Substitution der SnMe3-Gruppe in [C5H5(PMe3)2CoSnMe3]PF6 (11) durch SnCl4 bzw. HgCl2 führt zu [C5H5(PMe3)2CoSnCl3]PF6 (10) bzw. [C5H5(PMe3)2CoHgCl]PF6 (14). - Mit HgCl2 bildet 1 sowohl ein 1:1- als auch ein 1:2-Addukt (13 und 15). Strukturvorschläge für diese Verbindungen werden diskutiert.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Zur Diels-Alder-Reaktivität s-cis-fixierter 1,3-Diene (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 862-882 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Diels-Alder Reactivity of s-tis-Fixed 1,3-DienesContrary to the 1,2-dimethylenecycloalkanes 8-10 and 2,3-dimethylene-14-dioxane (6), the 4,5-dimethylene-1,3-dioxolanes 1-5 show very poor diene reactivities in the Diels-Alder reaction though possessing an s-cis-fixed diene system. This is documented by bimolecular rate constants as well as activation parameters. The influence of the ionisation potentials measured by PE spectroscopy and of the molecular geometries calculated by the MINDO/3 method on the reactivity is studied. It is shown that not the dehedral angle but the scissoring (1.4-distance) of the diene system is of decisive importance for the reactivity of the s-cis-fixed dienes.
    Notes: Die 4,5-Dimethylen-1,3-dioxolane 1-5 zeigen, obwohl sie s-cis-fixierte Diensysteme darstellen, im Vergleich zu den 1,2-Dimethylencycloalkanen 8-10 und 2,3-Dimethylen-1,4-dioxan (6) sehr geringe Dienreaktivitäten, wie durch die Geschwindigkeitskonstanten und die Aktivierungsparameter belegt wird. Der Einfluß der durch Photoelektronenspektroskopie festgelegten Ionisationspotentiale und der nach dem MINDO/3-Verfahren berechneten Molekülgeometrien auf die Reaktivität wird untersucht. Es zeigt sich, daß für die Reaktivität der s-cis-fixierten Diene nicht der Interplanarwinkel, sondern die Scherung (1,4-Abstand) des Dien-Systems von entscheidender Bedeutung ist.
    Additional Material: 9 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120312
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Der Einfluß des Dien-1,4-Abstandes auf die Reaktivität bei Diels-Alder-Reaktionen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 883-889 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Significance of Diene-1,4-Distance on the Reactivity in Diels-Alder ReactionsThe reactivity of cyclopentadiene and di-exo-methylene compounds in Diels-Alder reactions is investigated using the frontier molecular orbital method. It is shown that besides the HOMO-LUMO energy difference the diene 1,4-distance plays an important part for the rate of reaction. The shorter this distance is the higher becomes the reactivity. Experimentally this is shown by the rates of reaction of tetracyanoethylene and maleic anhydride with cyclopentadiene and di-exo-methylene compounds 2-6. The 1,4-distance of the latter is known from force field calculations. 1,4-Distance and log k2 exhibit a linear relationship which is supported by theoretical considerations.
    Notes: Die Reaktivität von Cyclopentadien und cis-fixierten Di-exo-methylenverbindungen in Diels-Alder-Reaktionen wird im Rahmen des Grenzorbitalmodells untersucht. Es wird gezeigt, daß neben der Energiedifferenz der dominanten Grenzorbitalwechselwirkung auch der Dien-1,4-Abstand eine wichtige Funktion besitzt. Je kürzer dieser ist, umso reaktiver ist das Dien. Dies zeigt die Kinetik der Umsetzung von Tetracyanethylen und Maleinsäureanhydrid mit Cyclopentadien und den Di-exo-methylenverbindungen 2-6, deren 1,4-Abstand auf Grund von Kraftfeldrechnungen bekannt ist. Zwischen 1,4-Abstand des Diens und log k2 der Cycloaddition besteht ein linearer Zusammenhang, der sich theoretisch begründen läßt.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120313
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Der Mechanismus der photolytischen Umsetzung von Pyridin mit Bis(trimethylsilyl)quecksilber, ein Beitrag zur metallorganischen Photochemie (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 950-956 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Mechanism of the Photolytic Reaction of Pyridine with Bis(trimethylsilyl)mercury, a Contribution to the Photochemistry with Metal AlkylsThe photolytic generation of N-(trimethylsilyl)pyridinyls 2 or. resp., their 4,4′-dimers from pyridine or its alkyl derivatives and bis(trimethylsilyl)mercury (1) involves surprisingly no free silyl radicals, but passes a long-lived, photoexcited, polar state 1a of the molecule 1. The latter is described more closely. It is complexed stepwise by two molecules of pyridine, and only in the last step free radicals are formed. The possibly more general importance of these findings for photolytic reactions with metal alkyls is pointed out.
    Notes: Die photolytische Bildung von W-(Trimethylsilyl)pyridinylen 2 bzw. ihren 4.4′-Dimeren. aus Pyridin bzw. seinen Alkylverbindungen und Bis(trimethylsilyl)quecksilber (1) verläuft überraschenderweise nicht über freie Silyl-Radikale, sondern über einen längerlebigen, photoangeregten, polaren Zustand la des Moleküls 1, über den nähere Aussagen gemacht werden. Er wird schrittweise durch zwei Moleküle Pyridin komplexiert, worauf erst im letzten Schritt freie Radikale entstehen. Auf die mögliche Bedeutung der Befunde für andere photolytische Reaktionen mit Metallalkylen wird hingewiesen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120318
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Cyclopropyl-Nachbargruppeneinfluß auf die Brückenkopfreaktivität von Verbindungen mit Bicyclo[2.2.2]octan-Grundgerüst (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 908-935 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclopropyl Neighbouring Group Influence on the Bridgehead Reactivity of Compounds with a Bicyclo[2.2.2]octane SkeletonUpon photochlorination with tert-butyl hypochlorite the cyclopropane anellated bicyclo[2.2.2]-octane hydrocarbons 10a and 2a-6a give the bridgehead chlorids 10b and 2b-6b in increasing relative yields. In addition, a more efficient directed synthesis for 2b has been developed. The solvolysis reactions of 2b-6b lead to unrearranged bridgehead derivatives exclusively, the substantially increasing rates in the series 2b-6b indicating, that a cyclopropyl group can stabilize a neighbouring carbenium ion center substantially, even if the system does not possess the best bisected conformation. It is only with a perpendicular arrangement of the axis of the carbenium ion p-orbital and the Walsh orbital at the neighbouring cyclopropyl carbon atom as in 10b that the cyclopropyl group exhibits a destabilizing effect exclusively. Analysis of the kinetic parameters leads to the result, that the skeletons of the intermediate carbenium ions from 2b, 5b and 6b are twisted with respect to those of the starting materials, because this apparently enables the intermediates to gain additional stabilization. However, for 3b and 4b the twisting in the ground and the transition state has to be equally small. For 2b and 5b-6b the twist angle decreases with an increasing number of anellated cyclopropane rings. The same conclusions have been drawn from the interpretation of the 13C-chemical shifts of the free bridgehead carbenium ions 2f and 4f-6f, which have been generated by the reaction of the corresponding chlorides with antimony pentafluoride in sulfuryl chloride fluoride.
    Notes: Bei der Photochlorierung mit tert-Butylhypochlorit entstehen aus den cyclopropan-anellierten Bicyclo[2.2.2]octan-Kohlenwasserstoffen 10a und 2a-6a mit ansteigenden Relativanteilen die Brückenkopfchloride 10b und 2b-6b. Die Solvolysereaktionen von 2b-6b führen ausschließlich zu nichtumgelagerten Brückenkopfderivaten; die in dieser Reihe erheblich ansteigenden Geschwindigkeiten - relativ zum 1-Bicyclo[2.2.2]octylchlorid um bis zu 2.8·108. beweisen, daß eine Cyclopropylgruppe auch bei einer von der optimalen bisektierten Anordnung abweichenden Konformation ein benachbartes Carbeniumionzentrum beträchtlich stabilisiert. Nur bei senkrechter Anordnung der Achsen des Carbeniumion-p-Orbitals und des Walsh-Orbitals am benachbarten Dreiring-C-Atom wie in 10b wirkt die Cyclopropylgruppe ausschließlich destabilisierend. Die Auswertung der kinetischen Parameter ergibt, daß die Gerüste der intermediären Carbeniumionen aus 2b, 5b und 6b im Vergleich zu denjenigen der Ausgangsverbindungen stärker verdrillt sind, weil dies offenbar eine zusätzliche Stabilisierung der Zwischenstufen ermöglicht. Bei 3b und 4b dagegen muß die Verdrillung von Ausgangs- und Übergangszustand gleich gering sein; bei 2b, 5b und 6b wird sie mit zunehmender Zahl anellierter Cyclopropanringe geringer. Zu den gleichen Schlußfolgerungen führt die Interpretation der 13C-chemischen Verschiebungen der freien Brückenkopf-Carbeniumionen 2f und 4f-6f, die aus den entsprechenden Chloriden mit Antimonpentafluorid in Sulfurylchloridfluorid erzeugt wurden.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120316
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...