ISSN:
0009-2940
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Contributions to the Synthesis and Structure of Tris(phosphonium) Methanide Salts and Their PrecursorsThe addition product of hexaphenylcarbodiphosphorane (1) and chlorodiphenylphosphane of the formula [(Ph3P)2CPPh2]⊕ Cl⊖ (7) was found to have inequivalent Ph3P groups by 31P NMR spectroscopy in solution at low temperatures, due to restricted rotation of the Ph2P group. The ground state corresponds to a conformation with the lone pair of electrons at PIII in the P3C plane. - The dication [(MePh2P)3C]2⊕ 2 I⊖ is obtained, as the diiodide 10, from MePh2P=CH2, and Ph2PCl followed by CH3I. In 10 all three MePh2P groups are equivalent (C3h-Symmetry). [(MePh2P)(Ph3P)2C]2⊕ 2 I⊖ (11) is prepared through CH3I addition to 7, [(MePh2P)(Ph2P)-(Ph3P)C]2⊕ 2 I⊖ (12) from 8 and CH3I. - Cyclic tris(phosphonium) methanides 14-16 are formed from 8 and 1,3-dibromopropane, 1,4-dibromobutane, and 1,2-bis(chloromethyl)benzene, respectively. The analogous process with 8 and 1,4-dibromo-2-butene yields a product 17 with a vinyl-substituted 1,3-diphospholane system.
Notes:
Das aus Hexaphenylcarbodiphosphoran (1) und Chlordiphenylphosphan erhaltene Produkt [(Ph3P)2CPPh2]⊕ Cl⊖ (7) besitzt in Lösung bei tiefen Temperaturen 13P-NMR-spektroskopisch inäquivalente Ph3P-Gruppen, was auf eine gehinderte Rotation der PPh2-Gruppe zurückzuführen ist. Dem Grundzustand entspricht eine Konformation mit dem freien Elektronenpaar am PIII-Atom in der P3C-Ebene. - Im Dikation [(MePh2P)3C]2⊕, als Diiodid 10 aus MePh2P=CH2, Ph2PCl und CH3I zugänglich, sind die drei MePh2P-Gruppen äquivalent (C3h-Symmetrie). Aus 7 und CH3I wird [(MePh2P)(Ph3P)2C]2⊕ 2I⊖; (11) erhalten, und aus Ph3P=C(PPh2)2 (8) entsprechend [(MePh2P)(Ph2P)(Ph3P)C]2⊕ I⊖ (13) und [(Ph3P)(MePh2P)2C]2⊕ 2I⊖ (12). - Cyclische Tris(phosphonium)-methanid-Salze 14-16 entstehen aus 8 und 1,3-Dibrompropan, 1,4-Dibrombutan und 1,2-Bis(chlormethyl)benzol. Die analoge Reaktion von 8 mit 1,4-Dibrom-2-buten ergibt ein Produkt mit vinylsubstituiertem 1,3-Diphospholansystem 17.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19831161105
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