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  • 1975-1979  (72)
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Year
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Accounts of chemical research 8 (1975), S. 62-70 
    ISSN: 1520-4898
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 97 (1975), S. 6281-6282 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Naturwissenschaften 62 (1975), S. 372-378 
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 2842-2850 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Reactions of Phosphorus Ylides with Silacyclobutanes, II. Ring-opening with Subsequent RecyclizationThe reactions of silacyclobutane (1) with trialkylalkylidenephosphoranes lead to silyl ylides of the type 2a-c through ring-opening and subsequent recyclization with elimination of molecular hydrogen. The unexpected constitution of these products can be interpreted by the assumption of a pentaalkylphosphorane intermediate. With the bulky triisopropylmethylenephosphorane, a silacyclobutyl ylide (4) is obtained. 1-Methylsilacyclobutane (5) is similar to 1 in its reactions, and methylated homologs 2e-g are obtained. 1,1-Difluorosilacyclobutane (6) is converted into cyclic fluorosilyl ylides (2h-j), through ring-opening followed by recyclization with HF-elimination, if the reactions with ylides are carried out in a 1:2 molar ratio.
    Notes: Die Reaktion von Silacyclobutan (1) mit Trialkylalkylidenphosphoranen führt nach Ringspaltung durch Recyclisierung unter Wasserstoff-Eliminierung zu den Silyl-yliden des Typs 2a-c. Die unerwartete Konstitution dieser Produkte ist durch Annahme einer Pentaalkylphosphoran-Zwischenstufe deutbar. Mit dem sperrigen Triisopropylmethylenphosphoran wird dagegen ein Silacyclobutyl-ylid (4) erhalten. 1-Methylsilacyclobutan (5) reagiert analog 1 zu den methylierten Homologen 2e-g. 1,1-Difluorsilacyclobutan (6) wird von den Yliden bei Ansätzen im Molverhältnis 1:2 unter Ringöffnung und nachfolgender Recyclisierung durch HF-Abspaltung in ringförmige Fluorsilyl-ylide 2h-j umgewandelt.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 109 (1976), S. 473-481 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectra and Structure of Arsenic Ylides. P Versus As: A Contribution to the Problem of Ylide BondingThe He (I) photoelectron spectra of the arsenic ylide (CH3)3 As=CH2 and its two trimethylsilyl derivatives (CH3)3 As=CHSi(CH3)3 and (CH3)3 As=C[Si(CH3)3]2 have been discussed and compared with the data existing for analogous phosphorus compounds. Using semiempirical MO calculations (CNDO, EHMO) and literature 13C data, a consistent model of the electronic structure has been obtained, which permitted a rationalization of the remarkable differences between the parent arsenic and phosphorus ylides and their mono- and bis-silyl derivatives. The ionisation potentials and the calculated total energies point to possible changes in the structure at the ylidic methyl anion upon a P/As substitution.
    Notes: Die He(I)-Photoelektronenspektren des Arsen-ylids (CH3)3 As=CH2 und seiner beiden Trimethylsilylderivate (CH3)3 As=CHSi(CH3)3 und (CH3)3 As=C[Si(CH3)3]2 wurden mit den für die analogen Phosphorverbindungen existierenden Daten vergleichend diskutiert. Zusammen mit semiempirischen MO-Rechnungen (CNDO, EHMO) und bekannten 13C-NMR-Daten ergibt sich ein konsistentes Modell zur Elektronenstruktur. Dieses gestattet die Rationalisierung der bemerkenswerten Unterschiede zwischen Arsen- und Phosphor-ylid-Grundkörper und deren Mono- und Bis-silylierungsprodukten. Ionisierungspotentiale und berechnete Gesamtenergien weisen auf mögliche Geometrieänderung am “ylidischen Methylanion” bei P/As-Austausch hin.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1312-1320 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reactions of Some Simple Alkylene and Imino ArsoranesTriethylmethylenearsorane (1) has been prepared through desilylation of a trimethylsilyl precursor and through dehydrohalogenation of triethylmethylarsonium salts by NaNH2. In the latter reaction (which is also applicable for (C6H5)3As = CH2), triethyl(imino)arsorane (2) is also formed with generation of methane. From tetramethylarsonium salts and NaNH2, (CH3)3As = NH is generated exclusively. These compounds are easily metallated at nitrogen and converted into their silyl derivatives. Triethylethylidenearsorane could not be isolated, but its trimethylsilyl compound 3b was readily obtained. Stable complexes with CuCl and AgCl were prepared from (C6H5)3As = CH2 (4).
    Notes: Triethylmethylenarsoran (1) wurde durch Entsilylierung einer Trimethylsilyl-Vorstufe (1b) und durch Dehydrohalogenierung von Triethylmethylarsoniumsalz mit NaNH2 dargestellt. Bei der letzten Reaktion (die entsprechend auch für (C6H5)3As = CH2 anwendbar ist)entsteht unter Methanentwicklung auch Triethyl(imino)arsoran (2). Aus Tetramethylarsoniumsalzen und NaNH2 wird ausschließlich (CH3)3As = NH erhalten. Diese Verbindungen sind am Stickstoffatom leicht metallier- und silylierbar. Triethylethylidenarsoran konnte nicht isoliert werden, wohl aber sein Trimethylsilyl-Derivat (3b). Von (C6H5)3As = CH2 (4) wurden stabile Komplexe mit CuCl und AgCl dargestellt.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1576-1585 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1-Methyl-1-methylene-1λ5-phosphorinane and Cyclopropyl(dimethyl)methylenephosphorane: Two Different Types of Ylides from an Analogous Reaction, and their ComplexesThe reaction of NaNH2 with (4-bromobutyl)- or (3-bromopropyl)-trimethylphosphonium bromide in THF under reflux yields the two title compounds 1 and 8, resp. At room temperature imide-bridged double ylides 2 and 10 are generated. The reaction path is interpreted. With copper, silver, and gold(I) chloride, the dimeric coinage metal complexes of these ylides are obtained. In the first case (with 1) the complexes are assigned a double spirocyclic structure (7a-c).
    Notes: Die Reaktion von NaNH2 mit (4-Brombutyl)- oder (3-Brompropyl)-trimethylphosphonium-bromid in siedendem THF liefert die beiden Titelverbindungen 1 bzw. 8. Bei Raumtemperatur entstehen imid-verbrückte Doppel-Ylide 2 bzw. 10. Der Reaktionsverlauf wird gedeutet. Mit Kupfer-, Silber- und Gold(I)-chlorid werden die dimeren Münzmetall-Komplexe der Ylide erhalten, denen im ersteren Fall (mit 1) eine doppelt spirocyclische Struktur zukommt (7a-c).
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1748-1754 
    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, I. Synthesis and Crystal Structure of Binuclear Gold(I) CompoundsBis(diphenylphosphino)methane forms 1:2 complexes of AuCl, Aul, and AuCH3 (1a-c). From 2,2-bis(diphenylphosphino)propane an analogous AuCl complex could also be obtained (2a). in addition to the usual analytical and spectroscopic characterization, Au-Mößbauer and Au-ESCA spectra have been recorded, and an X-ray analysis of 1a has been carried out. The results are of interest with respect to the short, but nonbonding Au—Au distance.
    Notes: Bis(diphenylphosphino)methan bildet 1:2-Komplexe mit AuCl, Aul und AuCH3 (1a-c). Auch von 2,2-Bis(diphenylphosphino)propan kann ein analoger AuCl-Komplex erhalten werden (2a). Zusätzlich zur üblichen analytischen und spektroskopischen Charakterisierung werden Au-Mößbauer- und Au-ESCA-Spektren aufgenommen und von 1a eine Röntgenstrukturanalyse angefertigt. Die Ergebnisse sind wegen des kurzen, aber nichtbindenden Au—Au-Abstandes von Interesse.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 2758-2764 
    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, III. AuII Compounds by Means of Oxidative Addition of HalogenOxidative addition of halogen to the 1:2 complexes of bis(diphenylphosphino)methane and -propane with AuCl (1a, 5) leads to products which are formulated partly as AuI/AuIII compounds (2a, b), but partly also as true AuII derivatives (6a, b). The addition of iodine to the AuI complex yields an adduct of the type 4. For the characterisation of the largely insoluble materials, infrared, Mössbauer, and ESCA spectroscopy have been employed.
    Notes: Durch oxidative Addition von Halogen an 1:2-Komplexe von Bis(diphenylphosphino)methan und -propan mit AuCl (1a, 5) entstehen Produkte, die teilweise als AuI/AuIII-Verbindungen (2a, b), teilweise aber auch als echte AuII-Derivate zu formulieren sind (6a, b). Die Anlagerung von Iod an den AuI-Komplex liefert nur ein Addukt vom Typ 4. Zur Charakterisierung der fast ausnahmslos unlöslichen Substanzen wurden die Infrarot-, Mössbauer-und ESCA-Spektroskopie herangezogen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 10
    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, II. Synthesis and Crystal Structure of Eight-membered Heterocycles of Gold(I) with Au-Au InteractionFrom bis[(chloroaurio)diphenylphosphino]methane (1) and additional bis(diphenylphosphino)-methane a metallocyclic complex 2 is formed which is only slightly dissociated in polar solvents. The chloride can be converted into a tetraphenylborate 3.  -  The X-ray structure analysis shows that the two gold atoms of the centrosymmetric eight-membered ring are surrounded by two phosphorus and one chlorine atom in an approximately trigonal planar configuration. The two metals form a surprisingly short Au-Au axis (296 pm), which lies perpendicular to the P2AuCl planes, indicating a transannular metal-metal interaction.
    Notes: Aus Bis[(chloroaurio)diphenylphosphino]methan (1) entsteht mit weiterem Bis(diphenylphosphino)methan eine metallocyclische Verbindung 2, die in polaren Lösungsmitteln nur wenig dissoziiert ist und in ein Tetraphenylborat 3 umgewandelt werden kann.  -  Die Röntgenstrukturanalyse zeigt, daß die beiden Goldatome des centrosymmetrischen achtgliedrigen Ringsystems angenähert trigonal planar von zwei Phosphoratomen und einem Chloratom umgeben sind. Gleichzeitig bilden die beiden Metalle eine auffallend kurze Au-Au-Achse (296 pm), die auf den P2AuCl-Ebenen senkrecht steht. Sie läßt auf eine transannulare Metall-Metall-Wechselwirkung schließen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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