Mono- and di-bridged heterobimetallic systems from group 5 hydride phosphido and hydride phosphino metalloligands. Crystal structure of Cp2Ta(H)( μ-H)( μ-PMe2)Cr(CO)4
摘要:
The trihydrides Cp2MH3 (M=Nb, Ta) react with chlorophosphines PR2Cl (R=Me, Ph) affording phosphonium salts [Cp2MH2(PR2H)](+), Cl- (2 (a, b) 2' (a, b)). Depending on the metal (Nb or Ta) and on the nature of the phosphine substituent (Me or Ph), deprotonation of these salts leads to hydride phosphino Cp2MH(PR2H) (3 (a, b) 3'a) or hydride phosphido Cp2TaH2(PPh2) (4'b) metalloligands. These two kinds of complexes are able to bind [M'(CO)(5)] or [M'(CO)(4)] (M' = Cr, Mo, W) organometallic fragments to give mono-or di-bridged heterobimetallic systems. The crystallographic analysis of Cp2Ta(H)(mu-H)(mu-PMe2)Cr(CO)(4) (7'aCr) is reported and discussed. (C) 1997 Elsevier Science S.A.
Ph2PCl easily inserts into the Ta-H bond of Cp(2)TaH(3) affording an ionic complex [Cp(2)TaH(2)(HPPh(2))]Cl (4). This species was deprotonated to give the first phosphido-substituted tantalocene complex Cp(2)TaH(2)PPh(2) (5), which was characterized by NMR spectroscopy and X-ray crystallography. Thermal decomposition of 5 as well as its reaction with HPPh(2) was studied.
作者:Gilles Boni、Olivier Blacque、Philippe Sauvageot、Nicolas Poujaud、Claude Moı̈se、Marek M Kubicki
DOI:10.1016/s0277-5387(01)01014-2
日期:2002.3
Abstract The aim of this paper is to look for a better knowledge of the behaviour of bent tantalocenes that bear hydrides, phosphorus PR2X (R=Me, Ph; X=H, lone pair) and cyclopentadienyl (Cp=C5H5, Cp′=C5H2tBu(Me)2, Cp*=C5Me5) ligands. An orbital control of regioselectivity of insertion of the PR2 phosphide fragment of chlorophosphines PR2Cl into the central TaH bond of trihydrides Cp2TaH3 leading