Platination of 6-phenylimidazo[2,1-b]thiazole at the imidazole N atom to give chloro(ethylenediamine)(6-phenylimidazo[2,1-b] thiazole)platinum(II) nitrate, [PtCl-(C2H8N2)(C11H8N2S)]NO3, is accompanied by a rotation of 49.3 (8) degrees of the phenyl ring and a loss of extended conjugation in the normally planar 6-phenylimidazo[2,1-b]thiazole molecule.