Oxidation products of vanadocene and of its permethylated analogue, including the isolation and the reactivity of the unsolvated [VCp2]+ cation

Article abstract of DOI:10.1021/om9809320

The one-electron oxidation of vanadocene, VCp₂, by [FeCp₂]⁺ in toluene affords the 14-electron [VCp₂]⁺ cation, which has been isolated as an unsolvated species for the first time. Vanadium hexacarbonyl reacts with VCp₂ to give the μ-isocarbonyl derivative Cp₂V(μ-OC)V-(CO)₅ as a transient species, which has been characterized in solution by IR analysis. By reaction of VCp₂ with V(¹³CO)₆ followed by treatment with ¹²CO, the ionic dicarbonyl derivative [VCp₂(¹²CO)₂][V(¹³CO)₆] is formed, thus showing that during the formation of the ionic compound no redistribution of the carbonyl ligands between the two metal centers occurs. Bis(cyclopentadienyl)vanadium(II) and Co₂(CO)₈ give Cp₂VCo(CO)₄, which slowly decomposes in solution even at low temperature to give [VCp₂(CO)₂][Co(CO)₄], which was identified by conventional methods, including single-crystal X-ray diffraction. The reactivity of the unsolvated [VCp₂]⁺ cation as well as that of the heterobimetallic compound containing vanadium and cobalt with several Lewis bases is reported.