ORGANO-TRANSITION-METAL CHEMISTRY OF HIGHLY FLUORINATED LIGAND SYSTEMS .14. VANADOCENE-HEXAFLUOROARSENATE COMPLEXES - STRUCTURE OF CP2V(ASF6)2 AND V-51-NMR SPECTRUM OF [CP2VCL2]+[ASF6]-

The reaction behaviour of Cp2VCl2 towards the oxidizers AsF5, ClF3/AsF5, ClF, [ClF2]+[AsF6]-and WF6 has been investigated. Whereas in the reaction of Cp2VCl2 with AsF5 in the presence of NaF the vanadocene species is oxidized to yield [Cp2VCl2]+[AsF6]-, Cp2VCl2 does not react either with WF6 or with ClF or [ClF2]+[AsF6]- in dilute solution. Similarly, the vanadium in Cp2VCl2 is not oxidized by treatment with ClF3/AsF5 in CFCl3 solution but gives Cp2VCl(AsF6), [ClF2]+[AsF6]-, AsF3 and Cl2. The reaction of Cp2VCl2 with three equivalents of AsF5 affords Cp2V(AsF6)2, Cl2 and AsF3 in quantitative yield. In the presence of anhydrous HF CP2VCl2 can be oxidized with either AsF5 or with AgAsF6 to give [Cp2V(AsF6)2]+[AsF6]-. The V-51 NMR spectrum of [Cp2VCl2]+[AsF6]- has been recorded. The structure of Cp2V(AsF6)2 has been determined by a single crystal X-ray diffraction study.