The synthesis, structural and magnetic characterisation of [V III3O(tmme)2(diimine)2Cl] [diimine = 2,2'-bipyridine (1) or 1,10-phenanthroline (2)] and (HNEt3) 2[VIII4O(tmme)4] (3) is reported, in which H3tmme is tris(mercaptomethyl)ethane, MeC(CH 2SH)3, the thiol analogue of the famous tripodal alcohol ligands typified by H3thme [tris(hydroxymethyl)ethane, MeC-(CH 2OH)3]. Complexes 1 and 3 have "T-shaped" and square topologies, respectively, and the latter is centred on a rare example of a square-planar oxide. The tri-thiolate ligands bind the periphery of the clusters and provide such strong antiferromagnetic exchange pathways that in both cases only a single total spin state is occupied up to room temperature, in the absence of metal-metal bonding. Magnetic data, electronic structure calculations and electrochemical data are reported. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA. Weinheim.