Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 3501-3507 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 3508-3516 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bestimmung der Molekülstruktur von Hexamethylcarbodiphosphoran in der Gasphase durch ElektronenbeugungDie Molekülstruktur von Hexamethylcarbodiphosphoran, (CH3)3P=C=P(CH3)3, wurde in der Gasphase durch Elektronenbeugung bestimmt. Die hauptsächlichen Bindungslängen (ra) sind P—C=181.4(3) pm, P=C=159.4(3) pm, C—H=108.9(4) pm. Die Winkel zwischen den P—C-(Methyl)-Bindungen betragen 101.4(3)°, der scheinbare P=C=P-Winkel 147.6(5)°. Die einzige fixierte Struktur, die die beste Anpassung an die Meßdaten ergibt, hat die Gesamtsymmetrie C2, doch wird für ein Modell mit freier Drehbarkeit um die P=C-Achse eine noch bessere Übereinstimmung gefunden. Daraus und aus anderen Hinweisen kann geschlossen werden, daß das Molekül einen symmetrischen Kreisel bildet und daß die P=C=P-Einheit in der gemittelten Struktur linear ist. Die beobachtete Schrumpfung geht danach auf eine sehr niedrige Beugungsfrequenz zurück, die zur scheinbaren Nichtlinearität führt.
    Notes: The molecular structure of hexamethylcarbodiphosphorane, (CH3)3P=C=P(CH3)3, in the gas phase has been determined by electron diffraction. Principle bond lengths (ra) are: P—C, 181.4(3) pm, P=C, 159.4(3) pm; C—H, 108.9(4) pm. The angles between the P—C (methyl) bonds are 101.4(3)°, and the apparent P=C=P angle is 147.6(5)°. The single structure that fits the experimental data closest has C2 overall symmetry, but an even closer fit is obtained if free rotation about the P=C bonds is assumed. This and other evidence indicates that the molecule is probably a symmetric top, and that the P=C=P unit is linear in the average structure, with shrinkage caused by a low frequency bending vibration giving rise to the apparent non-linearity.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 88 (1976), S. 542-543 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 15 (1976), S. 502-503 
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...