Low-valent vanadium catecholate clusters

A simple synthetic route to low-valent vanadium catecholate clusters, via solvothermal reaction of [V(acac)(3)] with catechols in alcohols, is presented. The syntheses and X-ray structures of [V(6)(III)O(dbcat)(4)(OMe)(8)(MeOH)(2)] (1; which has the Lindqvist structure), [V(6)(III)O(2)(dbcat)(2)(dbsq)(2)(acac)(2)(PhCO(2))(4)(EtO)(2)] (2; which could alternatively be formulated as [V(4)(III)V(2)(IV)O(2)(dbcat)(4)(acac)(2)(PhCO(2))(4)(EtO)(2)]) and [V(2)(IV)(dbcat)(4)(EtOH)(2)] (3) are reported (dbcat(2-) = 3,5-(t)Bu(2)-catecholate; dbsq(-) = 3,5-(t)Bu(2)-semiquinone). The X-ray structures of the primary products of the reactions of 1 and 3 with atmospheric oxygen, [V(6)O(3)("dbcat'')(4)(OMe)(8)] (4) and [V(2)O(2)("dbcat'')(4)] (5), are also reported-the assignments of redox states for these four-electron oxidised species are more ambiguous.