Rebecca H. Laye, Mark Murrie, Stefan Ochsenbein, Aidan R. Bell, Simon J. Teat, James Raftery, Hans-Ulrich Güdel and Eric J. L. McInnes
Solvothermal Syntheses of High-Nuclearity Vanadium(III) Clusters
Chem. Eur. J. 9, 6215-6220 (2003)                 

Abstract: Superheating alcohol solutions of simple trimetallic vanadium(III) precursors gives the octa- and decametallic vanadium(III) clusters [V₈(OEt)₈(OH)₄(O₂CPh)₁₂] (1) and [V₁₀(OMe)₂₀(O₂CMe)₁₀] (2). Cluster 2 is the largest vanadium(III) cluster synthesised to date. Thus solvothermal synthetic techniques are an excellent route to high-nuclearity vanadium(III) clusters. Both 1 and 2 consist of a planar or near-planar array of V^III ions. The metal ions in 1 are bridged by either a m₂-hydroxide and two m₂-benzoate groups or two m₂-ethoxides and a m₂-benzoate groups, the two bridging arrangements alternating around the ring. In 2 each pair of neighbouring metal ions is bridged by two m₂-methoxides and a m₂-acetate, and this molecule is the V^III analogue of Lippard's famous "ferric wheel". Preliminary magnetic susceptibility studies show the exchange coupling in both complexes to be antiferromagnetic in nature, with the coupling stronger in 1 than in 2.