F. Calderazzo et al., Oxidation products of vanadocene and of its permethylated analogue, including the isolation and the reactivity of the unsolvated [VCp2](+) cation, ORGANOMETAL, 18(13), 1999, pp. 2452-2458
The one-electron oxidation of vanadocene, VCp2, by [FeCp2](+) in toluene af
fords the 14-electron [VCp2](+) cation, which has been isolated as an unsol
vated 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 speci
es, 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(cyclopent
adienyl)vanadium(II) and Co-2(CO)(8) give Cp2VCo(CO)(4) which slowly decomp
oses in solution even at low temperature to give [VCp2(CO)(2)][Co(CO)(4)],
which was identified by conventional methods, including single-crystal X-ra
y 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.