Organometallic Oxides: Preparation and Properties of the Clusters [(η-C5Me5)V(μ3-O)]4 and [(η-C5Me5)V]4(μ-O)6 by Reductive Aggregation of (η-C5Me5)VCl2(O)

Abstract

Reduction of Cp*VCl2(O) (Cp* = η-C5Me5) by the powerful reductants sodium, potassium, magnesium, or calcium or the amalgams of these metals gave a mixture of the black cubane-like cluster [Cp*V(μ3-O)]4 and the black-green adamantane-like cluster [Cp*V]4(μ-O)6. A concurrent coproduct of the formation of [Cp*V]4(μ-O)6 was dark purple [Cp*V(μ-Cl)2]3. The formation of [Cp*V]4(μ-O)6 was favored in toluene, whereas [Cp*V(μ3-O)]4 was favored in tetrahydrofuran. The identity of the reductant did not influence the ratio of [Cp*V]4(μ-O)6 to [Cp*V(μ3-O)]4 produced. A scheme for the reduction is proposed; the key intermediate is [Cp*VClO]2. The cluster [Cp*V(μ3-O)]4 was paramagnetic (μeff = 2.35 μB at 3..