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
  • ASTROPHYSICS  (1,388)
  • Inorganic Chemistry  (727)
  • 1990-1994  (2,115)
  • 1930-1934
  • 1993  (2,115)
Collection
Keywords
Publisher
Years
  • 1990-1994  (2,115)
  • 1930-1934
Year
  • 11
    Electronic Resource
    Electronic Resource
    Reversibility of the [2 + 2] Cycloaddition of Isocyanates to Glycals (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 265-267 
    Details
    ISSN: 0009-2940
    Keywords: [2 + 2] Cycloaddition, reversible ; Glycals ; Isocyanates ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [2 + 2] Cycloadducts obtained by the addition of tosyl isocyanate to glycals (10 - 13) undergo retro-addition upon heating or even at room temperature. The rate of retro-addition increases with rising temperature and polarity of the solvent.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260136
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Synthesis and Aggregation Properties in Solution of a New Octasubstituted Copper Phthalocyanine: {2,3,9,10,16,17,23,24-Octakis-[(dioctylaminocarbonyl)methoxy]phthalocyaninato}copper(II) (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 269-271 
    Details
    ISSN: 0009-2940
    Keywords: Phthalocyanine, soluble ; Cation-induced phthalocyanine aggregates ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of the octasubstituted phthalocyanine 1, highly soluble in organic solvents, is described. Its aggregation properties in different solvents and in the presence of alkaline, alkaline earth, and ammonium salts are studied.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260137
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Organometall-Oxide  -  Höhervalente Derivate der d-Metall-Säuren, 6. Tris(3,5-dimethyl-1-pyrazolyl)boranato-substituierte Alkyl(dioxo)1-, Methylenphosphoranyl(dioxo)1- und s̰1-Allyl(dioxo)1-Komplexe des Molybdäns und Wolframs (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 289-296 
    Details
    ISSN: 0009-2940
    Keywords: Oxo complexes, organometallic ; Borato, hydrotris(3,5-dimethyl-1-pyrazolyl)1-, complexes ; Molybdenum complexes ; Tungsten complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organometallic Oxo Complexes  -  Highervalent Derivatives of the d-Metal Acids, 6.  -  Hydrotris(3,5-dimethyl-1-pyrazolyl)borato-Substituted Alkyl(dioxo)1-, Methylenephosphoranyl(dioxo)1-, and s̰1-Allyl(dioxo) Complexes of Molybdenum and TungstenTp*MoO2Cl (1) and Tp*WO2Cl (2) [Tp* = κ31-HB(3,5-Me2pz)3] react with trimethyl aluminium to form the corresponding dioxo(methyl) complexes Tp*MO2(CH3), M=Mo (3), W (4). An X-ray crystal structure analysis of 3 is performed. The less oxidizing tungsten complex 2 is alkylated by Grignard reagents to yield alkyl complexes of the type Tp*WO2R 5-7 [R=CH2SiMe3, CH2tBu and CH2C(Me)Ph2] and the s̰1-2-methallyl complex Tp*WO2(CH2CMe=CH2) 8. Reactions of 2 with methylenephorphoranes R3P=CH2 (R=iPr, Ph) give transylidation products Tp*WO2(CHPiPr3) (9) and Tp*WO2(CH-PPh3) (10). Hydrolysis of 10 leads to a trioxotungstate [Tp*WO3]- (11), stabilized by a hydroxyphosphonium cation.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    all-Homocalixarene: Carbocyclische Wirtverbindungen mit intra- und extraannularen Ligandarmen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2483-2491 
    Details
    ISSN: 0009-2940
    Keywords: Carbocycles ; Homocalixarenes ; Calixarenes, Homo- ; Large rings ; Macrocycles ; [2n]Metacyclophanes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: all-Homocalixarenes: Carbocyclic Host Compounds with Intra- and Extraannular Ligand ArmsMethoxy-substituted [2n]metacyclophanes 1-10, obtained by Müller-Röscheisen cyclization, are converted into all-homocalixarenes 11-20 with free phenolic hydroxy functions. The well-soluble cyclic pentamer 11 and octamer 14 with endo-acidic host properties are investigated with regard to guest binding. They exhibit selectivity towards alkaline earth metal ions (Ba2+) in liquid/liquid extraction studies. Some of the macrocyclic oligophenols are transformed into homocalixarenes 21-25 with intra- or extraannular oxapropionate groups. The diester 22 and the tetraester 23 are converted into carbocycles 26 and 27 with two and four free oxapropionic acid groups. Complexation properties of the oligoesters in extraction studies and log K values in water are reported. X-ray structural analyses were performed of the [6]-, [8]- and [4]- homocalixarenes 9 and 21, 14 and 23; the inclusion of solvent molecules is proven.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261123
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Preparation and Conformational Studies of Ethylene-Bridged Calixarene-Analogous Macrocyclic Metacyclophanes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2501-2504 
    Details
    ISSN: 0009-2940
    Keywords: [(2.1)n]Metacyclophanes, hydroxy- ; Calixarenes ; Trans-tert-butylation ; Conformation ; Hydrogen bonding, intramolecular ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The novel macrocyclic compounds hexahydroxy[2.1.2.1.2.1]- (7b) and octahydroxy[2.1.2.1.2.1.2.1]metacyclophane (7c) have been prepared from anisole in six steps by using the tert-butyl function as a positional protective group on the aromatic ring. Base-catalyzed condensation of 1,2-bis(5-tert-butyl-2-hydroxy-phenyl)ethane (5) with formaldehyde in refluxing xylene does not afford the dimeric product, tetrahydroxy[2.1.2.1]metacyclophane 6a, but furnishes the larger macrocycles 6b and 6c in 70-90% yield. AlCl3/MeNO2-catalyzed trans-tert-butylation of 6b and 6c in toluene gives the desired metacyclophanes 7b and 7c in 60 and 80% yields, respectively, along with tert-butyltoluene 8b. The conformations of the systems such as trimer 6b and tetramers 6c, 7c have been evaluated from their dynamic 1H-NMR spectra. The tetramer 6c is fixed to form a “pleated-loop” conformation like the calix[8]arenes due to the much more stronger intramolecular hydrogen bonding among the hydroxyl groups than in the trimer 6b.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261125
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Stereoselectivity of the Thermally Initiated Free-Radical Chain Addition of Cyclohexane to 1-Alkynes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2493-2499 
    Details
    ISSN: 0009-2940
    Keywords: Radicals ; Addition ; Stereoselectivity ; Alkynes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Alkanes can be added to alkynes in a thermally initiated free-radical chain reaction (“ane reaction”). The addition of cyclohexane to 1-alkynes 1a-1 yields a mixture of (Z)- and (E)-2-cyclohexyl-1-alkenes 3a-1. An essential step in this reaction is the addition of cyclohexyl radicals to the alkynes to give 2-cyclohexyl-1-alkenyl radicals 2a-1 which abstract hydrogen from cyclohexane to yield the products 3a-1. The stereoselectivity of the addition has been measured in the temperature range of 160-260°C. It strongly depends on the substituent X of the radical center and varies over a range of almost four orders of magnitude from [(Z)-3a]:[(E)-3a] = 33 (X = OMe) at 160°C to [(Z)-31]:[(E)-31] = 0.012 (X = tBu) at 260°C. The stereoselectivity is further influenced by the temperature and in most cases by the concentration of the hydrogen donor cyclohexane. The reaction is discussed in terms of the stereoselectivity of the addition of cyclohexyl radicals to the alkyne, of the structure of the 1-alkenyl radical (σ and π radical, respectively), the rate of inversion in the case of σ alkenyl radicals, and the relative rates of syn and anti hydrogen transfer.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261124
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Medium-Sized Cyclophanes, 29. Synthesis and Desulfurization of 2,11-Dithia[3]metacyclo- and 2,11-Dithia[3]paracyclo[3](4,9)pyrenophanes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2505-2511 
    Details
    ISSN: 0009-2940
    Keywords: Cyclophanes ; Benzenopyrenophane, 4,9-bridged ; Sulfones, pyrolysis of ; Photodesulfurization ; [2]Naphthaleno[2]paracyclophane, 1,5-bridged ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2,11-Dithia[3]metacyclo- (14b) and 2,11-dithia[3]paracyclo[3]-(4,9)pyrenophane (14c) were obtained by the coupling reactions of 4,9-bis(chloromethyl)pyrene (12) with the corresponding bis(mercaptomethyl)benzenes (13b, c). Attempted pyrolysis of the disulfones 18b, 18c to afford [2]metacyclo- (19b) and [2]paracyclo[2](4,9)pyrenophane (19c) failed. Only the ring cleavage products 16 and 20 were obtained. The sulfur dioxide extrusion by vapor-phase pyrolysis of the corresponding disulfone 18 to the highly strained 19 clearly demonstrates the limits of these preparative ring contraction method. The photolytic desulfurization of 14c afforded the [2](1,5)naphthal-eno[2]paracyclophane analogue 21 instead of [2]paracyclo[1]-(4,9)pyrenophane 21′. The mechanism of the pyrolysis and photolysis reactions is discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261126
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Flow-Vacuum Pyrolysis of Polycyclic Compounds, 6. Pyrolysis of Dibenzo [CH]8 Hydrocarbons (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2513-2517 
    Details
    ISSN: 0009-2940
    Keywords: Dibenzo [CH]8 hydrocarbons ; Flow-vacuum pyrolysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The flow-vacuum pyrolysis of dibenzo [CH]8 hydrocarbons 2,3,4, and 5 are studied at 1 Torr and in the temperature range between 400 and 650°C. The following new transformations have been observed: 2⇆4, 2→5, 3→5, 3⇆4, 3→2, 5→11, the last three presenting analogies in the [CH]8 and/or benzo [CH]8 series. A reaction mechanism is suggested.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261127
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    On the Reaction of 1-Aza-2-azoniaallene Salts with Carbodiimides (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2519-2524 
    Details
    ISSN: 0009-2940
    Keywords: 1-Aza-2-azoniaallene cations ; Carbodiimides ; 1H-1,2,4-Triazolium salts ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1-Aza-2-azoniaallene cations 3, prepared in situ from geminal (chloroalkyl)azo compounds 2, react with carbodiimides 4 to give 4,5-dihydro-5-imino-1H-1,2,4-triazolium salts 7. An X-ray structural analysis was carried out for 71. According to AM1 calculations the cycloaddition of carbodiimides to 1-aza-2-azoniaallene cations occurs in a nonconcerted manner via cyanamidium cations 5 as intermediates. Hetero-Wagner-Meerwein rearrangements of the primary cycloadducts 6 provide the final products 7.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261128
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Organophosphorverbindungen, 73. Der Tri-tert-butyl-2-cyclopropen-1-yl-Rest als kinetisch stabilisierende Gruppe für 1-Aza-3-phosphaallene (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2525-2530 
    Details
    ISSN: 0009-2940
    Keywords: Phosphanes, cyclopropenyl- ; Phosphaalkenes, cyclopropenyl ; Shifts, [1,3]-silyl and [1,3]-H ; 1-Aza-3-phosphaallenes ; Cyclopropenyl substituents ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organophosphorus Compounds, 73[1]. - The Tri-tert-butyl-2-cyclopropen-1-yl Substituent as Kinetically Stabilizing Group for 1-Aza-3-phosphaallenes[2]The cyclopropenylphosphane 5 reacts with the isocyanates 6a-g to form the phosphaalkenes 7a-g. An analogous transformation occurs with the same phosphane and the bifunctional isocyanates 8a, b (→ 9a, b). In contrast, the reaction 5 + 6h ends at the stage of the tautomers 11h ⇆ 12h. Methanolysis of 7b and of 11h ⇆ 12h leads to the carbamoyl-cyclopropenylphosphanes 14a and b, respectively. Sodium hydroxide-catalyzed elimination of hexamethyldisiloxane from 7b, g and the tautomer mixture 11h ⇆ 12h yields the target 1-aza-3-phosphaallenes 16a-c.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261129
    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...