Chemical one-electron oxidation of [Pt-II(3,5-DTBCat)(DTBbpy)] (1) (3,5-DTBCat = 3,5-di-tert-butyl catecholato, DTBbpy = 4,4'-di-tert-butyl-2,2'-bipyridine) afforded the corresponding paramagnetic complex, [Pt-II(3,5-DTBSQ)(DTBbpy)]+PF6- (1(PF6)), as a result of ligand-centred oxidation. While complex 1 is relatively stable in common organic solvents, the present study demonstrates that cationic [1](+) is subject to an unprecedented solvent-induced disproportionation in highly polar solvents such as DMSO and DMF, which results in the formation of 1 and a free benzoquinone.