Electron spin resonance studies of ziegler-type catalysts. Part 2. Identification and spectra of some dialkyldi(η-cyclopentadienyl)vanadium(IV) complexes
Abstract
E.s.r. evidence has been obtained for the formation of [VEt2(cp)2] on reaction of ethyl-lithium with [VCl2(cp)2](cp =η-cyclopentadienyl), and for [V(CH2SiMe3)2(cp)2] from the reaction of trimethylsilylmethyl-lithium, or the corresponding Grignard reagent, with [VCl2(cp)2]. The results have also been examined by a theoretical treatment. The Aiso, and giso, values for [VEt2(cp)2] and [V(CH2SiMe3)2(cp)2] are 6.24 mT and 1.995 and 6.45 mT and 1.990 respectively.