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

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 reads with VCp2 to give the mu-isocarbonyl derivative Cp2V(mu-OC)V(CO)(5) as a transient species, which has been characterized in solution by IR analysis. By reaction of VCp2 with V((CO)-C-13)(6) followed by treatment with (CO)-C-12, the ionic dicarbonyl derivative [VCp2((CO)-C-12)(2)][V((CO)-C-13)(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 Co-2(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.