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  • 1
    Electronic Resource
    Electronic Resource
    Doppelylide, II. Synthese, Eigenschaften und eine Kristallstrukturbestimmung einiger [Methanidobis(dimethylphosphonium-methylid)]-Komplexe von Haupt- und Nebengruppenmetallen (Al, Ga, Ni, Pd, Pt, Au, Zn, Cd) (1977)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 3517-3527 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Double Ylides, II. Synthesis, Properties, and a Crystal Structure Analysis of Some [Methanidobis(dimethylphosphonium methylide)] Complexes of Main Group and Transition Metals (Al, Ga, Ni, Pd, Pt, Au, Zn, Cd)The cyclic dimethylaluminium complex 1 with the novel methanidobis(dimethylphosphonium methylide) ligand is easily accessible from Li[Al(CH3)4] and (CH3)3PCHP(CH3)3F in good yields. The analogous gallium compound 2 is obtained from (CH3)3Ga etherate and (CH3)3-P=C=P(CH3)3. The X-ray structure analysis of 2 has shown that this compound forms six-membered rings with a quasi-tetrahedral configuration of substituents at the Ga and P atoms, which are bridged by two CH2 and one planar CH bridge (PCHP). (CH3)3PCP(CH3)3 undergoes a transylidation reaction with nickel, palladium, and platinum dichloride to yield novel chelate complexes, in which each methanidobis(dimethylphosphonium methylide) ligand is attached to the central atom through two metal-carbon σ-bonds. For these complexes a centrosymmetrical square-planar structure is proposed. Accordingly, with (CH3)3AuCl a dimethylgold chelate complex 4 is obtained.  -  From zinc and cadmium alkyls, upon reaction with 1 the ylide complexes 5a, b with tetrahedral configuration are formed with evolution of alkane.
    Notes: Der cyclische Dimethylaluminium-Komplex 1 mit dem neuartigen Methanidobis(dimethylphosphonium-methylid)-Liganden ist aus Li[Al(CH3)4] und (CH3)3PCHP(CH3)3F gut zugänglich. Die analoge Galliumverbindung 2 kann aus (CH3)3Ga-Etherat und (CH3)3P=C=P(CH3)3 erhalten werden. Die Röntgenstrukturanalyse von 2 ergab, daß diese Verbindung Sechsringmoleküle mit quasi-tetraedrisch konfigurierten Ga- und P-Atomen enthält, die über zwei CH2-und eine planare CH-Brücke (PCHP) verknüpft sind. (CH3)3PCP(CH3)3 reagiert mit Nickel-, Palladium- und Platindichlorid unter Umylidierung zu Chelatkomplexen (3a-c), in denen der Methanidobis(dimethylphosphonium-methylid)-Ligand über je zwei echte Metall-Kohlenstoff-σ-Bindungen an das Zentralatom fixiert ist. Für diese Komplexe wird eine centrosymmetrische quadratisch-planare Struktur vorgeschlagen.  -  Mit (CH3)2AuCl wird entsprechend ein Dimethylgold-Chelatkomplex 4 erhalten.  -  Aus Zink- und Cadmiumalkylen entstehen unter Alkanentwicklung die vermutlich tetraedrisch konfigurierten Ylidkomplexe 5a, b.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19771101107
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  • 2
    Electronic Resource
    Electronic Resource
    Anthracen-Addukte der Cyclopentenone (1959)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 92 (1959), S. 1970-1972 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Darstellung der Cyclopentenon-Anthracen-Addukte I und II wird beschrieben.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19590920833
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  • 3
    Electronic Resource
    Electronic Resource
    Doppelylide, I. Synthese und Eigenschaften von Hexamethyl- und sym-Tetramethyldiphenylcarbodiphosphoran (1977)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 3501-3507 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Double Ylides, I Synthesis and Some Properties of Hexamethyl- and sym-TetramethyldiphenylcarbodiphosphoraneHexamethylcarbodiphosphorane, (CH3)3P=C=P(CH3)3 (1), can be prepared by heating of a mixture of (CH3)3P=CHP(CH3)3F (2a) with NaH, or from 2a with n-BuLi. 2a is obtained by the reaction of (CH3)3PF2 with the ylides (CH3)3P=CH2 or (CH3)3P=CHSi(CH3)3 with elimination of [(CH3)4P]F or (CH3)3SiF, resp. The reaction of the chlorides [(CH3)3PCHP(CH3)3]C1 (2b) and [(CH3)3PCH2P(CH3)3]C12 (3b) with n-BuLi yields also 1. Spectroscopic data indicate a high carbanionic character for the central carbon in 1. No non-cumulated isomers (1a, b) have been detected. With (CH3)3SiC1, a side-chain derivative (CH3)3P=CH—P(CH3)2=CHSi(CH3)3 (4) is formed in a transylidation reaction. C6H5(CH3)2P=C=P(CH3)2C6H5 (6) was prepared from the corresponding dibromide 5 with NaNH2 in THF. Contrary to compound 1, this yellow double ylide is a labile compound.
    Notes: Hexamethylcarbodiphosphoran, (CH3)3P=C=P(CH3)3 (1), ist durch trockene Destillation der Mischung von (CH3)3P=CHP(CH3)3F (2a) mit NaH oder aus 2a und n-Butyllithium darstellbar. 2a entsteht aus (CH3)3PF2 mit den Yliden (CH3)3P=CH2 oder (CH3)3P=CH—Si(CH3)3 unter Abspaltung von [(CH3)4P]F bzw. (CH3)3SiF. Auch [(CH3)3PCHP(CH3)3]C1 (2b) und [(CH3)3PCH2P(CH3)3]C12 (3b) ergeben mit n-BuLi die Verbindung 1. Nach spektroskopischen Daten besitzt 1 eine hohen Carbanioncharakter am zentralen C-Atom. Nichtkumulierte Isomere 1a, b wurden nicht gefunden. Mit (CH3)3SiCi entsteht unter Umylidierung das Seitenkettenderivat (CH3)3P=CH—P(CH3)2=CHSi(CH3)3 (4). - C6H5(CH3)2P=C=P(CH3)2C6H5 (6) wurde aus dem korrespondierenden Dibromid 5 mit NaNH2 im THF dargestellt. Das gelbe Doppelylid ist im Gegensatz zu 1 leicht zersetzlich.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19771101105
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  • 4
    Electronic Resource
    Electronic Resource
    The 6Li,6Li-INADEQUATE Experiment: A New Tool for 1D- and 2D-NMR Studies of Organolithium CompoundsNMR Spectroscopy of Organolithium COmpounds, Part XIII. Part XII: [1]Dedicated to Prof. Adalbert Maercker on the occasion of his 60th birthday (1992)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 75 (1992), S. 883-891 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 1D- and 2D-6Li, 6Li-INADEQUATE experiments are described as new tools for the detection of scalar coupled nonequivalent 6Li nuclei in organolithium clusters. Practical applications of these sequences are demonstrated for the 6Li-NMR spectra of (E)-1-lithio-2-(2-lithiophenyl)-1-phenylhex-1-ene (1) and (E)-2-lithio-1-(2-lithiophenyl)-1-phenylpent-1-ene (2), where signals due to dimers and monomers can be distinguished. The performance of the 2D-6Li, 6Li-INADEQUATE and the 6Li, 6Li-COSY-45-LR experiment are compared. The 6Li chemical shifts of 1 and 2 are discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19920750322
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  • 5
    Electronic Resource
    Electronic Resource
    Synthese, Kristallstruktur und thermische Entwässerung von CsMnF4 · 2H2OZum ehrenden Andenken an Prof. Dr. Dr. h.c. Hans Schmid (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1589-1600 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis, crystal structure and thermal dehydration of CsMnF4 · 2H2OThe preparation of a new fluoromanganate (III)-complex CsMnF4 · 2H2O is reported. It crystallizes in the monoclinic space group C2 with a = 11.891(2) Å, b = 6.589(1) Å, c = 10.558(1) Å, β = 131.46(1)° and Z = 4. The crystal structure has been solved from diffractometer data by heavy-atom methods and refined to a conventional R-value of 1.8% (including the contributions of three hydrogen atoms in measured and one in calculated positions). The structure is characterized by isolated, tetragonally distorted [MnF4(OH2)2]-octahedra with Mn-F-distances from 1.801(8) Å to 1.870(7) Å and Mn-O-distances of 2.146(6) Å and 2.268(6) Å. Cesium exhibits an irregular 10-coordination by 8 F-atoms and 2 O-atoms (mean values for the two independent cesium ions: Cs-F = 3.17 Å and 3.21 Å, Cs-O = 3.32 Å and 3.29 Å). The [MnF4(OH2)2]-octahedra are connected to six neighbouring octahedra by hydrogen bonding.The dehydration of the complex has been studied by thermoanalytical methods and power x-ray-diffractometry. The unit cell of the dehydrated compound, CsMnF4, is tetragonal with a = 7.936(1) Å and c = 6.341(1) Å. A close relationship to the structure of CsFeF4, which is a superstructure variant of the T1A1F4-type[6], is indicated by the similarity of the corresponding unit cells and preliminary structure factor calculations. A proposition for the crystal structure of CsMnF4 is developed on the basis of (2 + 2 + 2)-orthorhombic distorted MnF6-octahedra.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19770600515
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  • 6
    Electronic Resource
    Electronic Resource
    Vicinal 2H/1H Isotope Shifts for 6Li-NMR and the Aggregation Behavior of Phenyllithium‘NMR Spectroscopy of Organolithium Compounds’, Part XIV; Part XIII: [l].Part of the Ph.D. thesis of O. E., University of Siegen, 1991.Dedicated to Professor Emanuel Vogel on the occasion of his 65th birthday (1992)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 75 (1992), S. 2553-2562 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vicinal deuterium-induced 6Li-NMR isotope shifts have been found for (D5)phenyllithium. These shifts are to low field, and their magnitude varies from 7 to 19 ppb with different solvents and donor molecules. On the basis of the isotopic fingerprints observed in the 6Li-NMR spectra of C6H56Li/C6D56Li mixtures, the aggregation behaviour of phenyllithium under different solvent conditions and in the presence of amines as donor ligands (TMEDA, PMDTA) was studied. Tetramers and dimers are observed in Et2O, dimers as well as momomers in Et2O/TMEDA and in THF, and momomers in THF/PMDTA. The hitherto unidentified species in Et2O/TMEDA was shown to be a monomer.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19920750810
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  • 7
    Electronic Resource
    Electronic Resource
    Solution-Structure and Aggregation Behavior of Two Dilithiostyrene Derivatives‘NMR Spectroscopy of Organolithium Compounds’, Part XVIII; Part XVII: [1].Dedicated to Professor Dr. Wolfgang Lüttke on the occasion of his 75th birthday (1995)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 78 (1995), S. 1913-1932 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The solution structure and the aggregation behavior of (E)-2-lithio-1-(2-lithiophenyl)-1-phenylpent-1-ene (1) and (Z)-2-lithio-1-(2-lithiophenyl)ethene (2) were investigated by one- and two-dimensional 1H-, 13C-, and 6Li-NMR spectroscopy. In Et2O, both systems form dimers which show homonuclear scalar 6Li,6Li spin-spin coupling. In the case of 2, extensive 6Li,1H coupling is observed. In tetrahdrofuran and in the presence of 2 mol of N,N,N′,N′-tetramethylethylylenediamine (tmeda), the dimeric structure of 1 coexists with a monomer. The activation parameters for intra-aggregate exchange in the dimers of 1 and 2 (1 (Et2O): ΔH≠ = 62.6 ± 13.9 kJ/mol, ΔS≠ = 5.8 ± 14.0 J/mol K, ΔG≠(263) = 61.1 kJ/mol; 2 (dimethoxyethane): ΔH≠ = 36.9 ± 6.5 kJ/mol, ΔS≠ = -61 ± 25 J/mol K, ΔG≠(263) = 54.0 kJ/mol) and the thermodynamic parameters for the dimer-monomer equilibrium for 1 (ΔH°; = 26.7 ± 5.5 kJ/mol, ΔS° = 63 ± 27 J/mol K), where the monomer is favored at low temperature, were determined by dynamic NMR studies.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19950780804
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  • 8
    Electronic Resource
    Electronic Resource
    On the Influence of Cholesterol Feeding and of a Lipogenic Diet on the Cholesterogenesis in Rat Liver in vivo (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2686-2694 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (1)The existence of a main regulation site(s) of the cholesterol synthesis located after the squalene formation is demonstrated by cholesterol feeding with labelled glucose, acetate, mevalonate as precursors and by measuring the incorporation rates into cholesterol, squalene, ubiquinones, and fatty acids in rat liver in vivo.(2)By administration of labelled squalene in vivo it is shown that the isoprenic synthesis is inhibited between squalene and lanosterol but that other regulation site(s) after the lanosterol formation must exist.(3)A regulation site of the cholesterogenesis in rat liver located after the squalene synthesis is also shown after a lipogenic diet administered during 5 days. The cholesterol synthesis is thus reduced to about one third of the control rats. Another regulating site controlling the utilization of acetylcoenzyme A for the synthesis of mevalonate is also shown to exist. No indication was obtained for a regulating influence located between mevalonate and squalene.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19770600819
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  • 9
    Electronic Resource
    Electronic Resource
    2H/1H Isotope Shifts for 6Li-NMR: First Experimental Detection and Applications to Structural Problems in the Field of Organolithium CompoundsNMR Spectroscopy of Organolithium Compounds, XI; earlier papers in this series: [1]Presented in part at the 10th European Experimental NMR Conference', Veldhoven, Netherlands, 28.5.-1.6.1990Dedicated to Professor P. von Ragué Schleyer on the occasion of his 60th birthday (1990)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 73 (1990), S. 2071-2082 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Deuterium-induced isotope effects on 6Li chemical shifts, transmitted over two bonds, 2Δ(6Li)(2H/1H), have been measured for the first time for methyllithium and the system methyllithium/lithium iodide. The observed shifts are to low field and range from 15 to 20 ppb per CD3 group. The multiplicity and intensity distribution of the 6Li signals resulting for mixtures of CH3- and CD3-containing samples in the limit of slow inter- as well as intra-aggregate exchange yield information about the size of the various clusters present in diethylether solution. It is expected that these isotope shifts can facilitate structural investigations of organolithium compounds. In some cases, the results of such measurements are expected to be less ambiguous then the conclusions based on multiplets that arise from scalar 13C,6Li spin-spin coupling.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19900730802
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  • 10
    Electronic Resource
    Electronic Resource
    Bausteine von Oligosacchariden, XXIX. Synthese des Trisaccharids aus N-Acetylglucosamin, Galactose und Rhamnose einer O-determinanten Kette von Escherichia Coli (1981)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 114 (1981), S. 3079-3101 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Building units for Oligosaccharides, XXIX. Synthesis of a Trisaccharide Chain of N-Acetylglucosamine, Galactose and Rhamnose of an O-Determinant from Escherichia coli. Dependence of Stereoselectivity of the α-Glycoside Synthesis on the Reactivity of the PyranosylhalideThe mercury salt catalysed reaction of substituted α-D-galactosyl halides with the reactive 4-OH groups of the rhamnosides 18 and 19 were studied. The order of reactivity of the halides increases with the following substituents: O-acetyl 〈 O-glucosyl 〈 O-benzyl. The order of selectivity, towards the α-glycoside, was the reverse. The selectivity can be improved by either decreasing the reactivity of the glycosyl halide, in the case of highly reactive hydroxyl groups, or by decreasing the nucleophilicity of the hydroxyl groups, in the case of highly reactive halides. Various trisaccharides, like 58 which represents the repeating-unit of the lipopolysaccharide from Escherichia coli O 75, were synthesized from N-acetylglucosamine, galactose and rhamnose.
    Notes: Die Quecksilbersalz-katalysierte α-Glycosidsynthese von gemischt substituierten α-D-Galactosylhalogeniden mit den reaktiven 4-OH-Gruppen der Rhamnoside 18 und 19 wird untersucht. Die Reaktivität der Halogenide nimmt bei Anwesenheit der folgenden Substituenten zu: O-Acetyl 〈 O-Glycosyl 〈 O-Benzyl. Parallel dazu nehmen die Selektivität und der Anteil and α-Glycosid ab. Notwendige Selektivitätsverbesserungen können bei zu reaktiven OH-Gruppen durch Verminderung der Reaktivität des Glycosylhalogenids, bei zu reaktiven Glycosylhalogeniden durch Verminderung der Reaktivität der OH-Gruppe erzielt werden. Verschiedene Trisaccharideinheiten aus N-Acetylglucosamin, Galactose und Rhamnose werden synthetisiert, wobei 58 einer Teil-struktur der repeating-unit der O-Determinante des Lipopolysaccharids aus Escherichia coli O 75 entspricht.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19811140915
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