Preparation and characterization of mono-cyclopentadienylvanadium dihalide bis-phosphine complexes; crystal structure of (η 5-C 5H 5)VCL 2(PMe 3) 2

Abstract

Mono-cyclopentadienyl complexes CpVX 2(PR 3) 2 and Cp′VX 2 (PR 3) 2 (Cp = η 5- C 5H 5; Cp′ = η 5-C 5H 4Me; R = Me, Et; X = Cl, Br) have been prepared by reaction of VX 3(PR 3) 2 with CpM (M = Na, T1, SnBu n 3, 1/2 Mg) or Cp′Na. Attempts to prepare analogous complexes with other phosphine ligands, PPh 3, PPh 2 Me, PPhMe 2, Pcy 3, DMPE and DPPE failed. Reduction of CpVCl 2(PEt 3) 2 with zinc or aluminium under CO (1 bar) offers a simple method for the preparation of CpV(CO) 3(PEt 3). The crystal structure of the trimethylphosphine complex CpVCl 2(PMe 3) 2 is reported.