Reaction of [PtCl2(dmso)(2)] with 2,5-(dialkoxyphenyl)pyridine in HOAc leads to a dinuclear, acetate-bridged, metal-metal bonded complex of platinum(III); dmso in the presence of acid is found to be responsible for the oxidation. The dimer is analogous structurally to Pd-III dimers implicated in catalytic acetoxylation. Platinum dimers with longer alkoxy chains are shown to be unique examples of liquid crystals of platinum(III).