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  • Wiley-Blackwell  (2)
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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 610 (1992), S. 75-82 
    ISSN: 0044-2313
    Keywords: Diphosphiranes ; phospharsiranes ; syntheses ; nmr data ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Properties of Pentamethylcyclopentadienylsubstituted PPC and AsPC three-membered RingsVia the reaction of bis-(pentamethylcyclopentadienyl)diphosphene [Cp*P=PCp*, 1] and 1-(pentamethylcyclopentadienyl)-2-(2,4,6-tritbutylphenyl)- diphosphene [Cp*P=PMes*, 2] with the diazomethanes N2CHR [R = H, Si(CH3)3] the four new diphosphiranes Cp*PPCp*CHSi(CH3)3, 4a, Cp*PPMes*CHSi(CH3)3, 4b, Cp*PPCp*CH2, 5a, Cp*PPMes*CH2, 5b, are obtained. The formation of 4a results via a 2 + 3-cyclo-addition product, which could be proved by nmr spectroscopy. The reaction of As-(pentamenthylcyclopentadienyl)-P-(2,4,6-tritbutylphenyl) arsaphosphene [Cp*As=PMes*, 3] with diazomethane leads to 1-(pentamethylcyclopentadienyl)-2-(2,4,6-tritbutylphenyl)-1-arsa-2 -phosphacyclopropane [phospharsiran, Cp*AsPMes*CH2, 6]. Analysis of the structures by nmr spectroscopy gives clear evidence for a trans-orientation of the substituents at the El—P bond (El = As, P) in all of the three membered ring systems. For the diphosphirane Cp*PPCp*CH2 (5a) a Cp*-phosphorus bond cleavage by thermolysis cannot be observed. From the reaction of compound 5a with Cr(CO)5thf one obtains 1-(pentacarbonylchrom)-1,2-bis(pentamethylcyclopentadienyl)-1,2- diphosphacyclo-propane, 7.
    Notes: Durch die Umsetzung von Bis-(pentamethylcyclopentadienyl)diphosphen [Cp*P=PCp*, 1] und 1-(Pentamethylcyclopentadienyl)-2-(2,4,6-tritbutyl-phenyl) -diphosphen [Cp*P=PMes*, 2] mit den Diazomethanen N2CHR [R = H, Si(CH3)3] erhält man die vier neuen Diphosphirane Cp*PPCp*CHSi(CH3)3, 4a, Cp*PPMes*CHSi(CH3)3, 4b, Cp*PPCp*CH2, 5a, Cp*PPMes*CH2, 5b. Die Bildung von 4a verläuft über ein 2 + 3-Cycloadditions-Produkt, welches NMR-spektroskopisch nachgewiesen werden konnte. Die Reaktion des As-(Pentamethylcyclopentadienyl)-P-(2,4,6-tritbutylphenyl) arsaphosphens [Cp*As = PMes*, 3] mit Diazomethan führt zum 1-(Pentamethylcyclopentadienyl)-2-(2,4,6-tritbutylphenyl)-1-arsa-2 -phosphacyclopropan [Phospharsiran, Cp*AsPMes*CH2, 6]. Die Strukturaufklärung anhand der NMR-Spektren ergibt für alle Dreiring-Systeme eine trans-Stellung der Substituenten an der El—P-Bindung (El = As, P). Beim Diphosphiran Cp*PPCp*CH2 (5a) wird keine thermische Spaltung der Cp*-Phosphor-Bindung beobachtet. Aus Verbindung 5a erhält man mit Cr(CO)5THF die Verbindung 1-(Pentacarbonylchrom)-1,2-bis(pentamethylcyclopentadienyl)-1,2- diphosphacyclopropan, 7.
    Additional Material: 1 Tab.
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  • 2
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Phosphorus. 197. Octa-tert-butyldodecaphosphane (8), P12(t-Bu)8 - Preparation and Structure Determination of Two Constitutional Isomers by Nuclear Magnetic ResonanceOcta-tert-butyldodecaphosphane(8) (1) has been obtained by thermolysing P6(t-Bu)4 and has been isolated in pure form. In addition, other tert-butylphosphanes, mainly P8(t-Bu)6 and P9(t-Bu)3, are formed. Compound 1 is produced as a mixture of two constitutional isomers 1a and 1b of comparable abundance, which could be separated by chromatography. According to the 2D-31P{1H}-NMR spectrum, 1a is 2,4,6,7,8-penta-tert-butyl-3-(2,3,4-tri-tert-butylcyclotetraphosphanyl)bicyclo[3.3.0]octaphosphane and 1b is the isomer with the cyclotetraphosphanyl substituent in the 2 position. In both cases, the P12(8) skeleton consists of a P8(6) partial structure analogous to that of pentalane and a monocyclic P4(4) partial structure which are linked through a σ-bond.
    Notes: Octa-tert-butyl-dodecaphosphan(8) (1) wurde durch Thermolyse von P6(t-Bu)4 neben anderen tert-Butylphosphanen, vor allem P8(t-Bu)6 und P9(t-Bu)3, gewonnen und analysenrein isoliert. Verbindung 1 entsteht als Gemisch von zwei Konstitutionsisomeren 1a und 1b annähernd gleicher Häufigkeit, die chromatographisch getrennt werden konnten. Nach dem 2D-31P{1H}-NMR-Spektrum handelt es sich bei 1a um 2,4,6,7,8-Penta-tert-butyl-3-(2,3,4-tri-tert-butylcyclotetraphosphanyl)bicyclo[3.3.0]octaphosphan, bei 1b um das Isomer mit dem Cyclo-tetraphosphanyl-Substituenten in 2-Position. In beiden Fällen besteht das P12(8)-Gerüst aus einem Pentalan-analogen P8(6)- und einem monocyclischen P4(4)-Teilgerüst, die über eine σ-Bindung verknüpft sind.
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