A series of trans-[PtCl 2(C 2H 4)L] [L = QNO (quinoline N-oxide), IQNO (isoquinoline N-oxide), 4-ClQNO, 2-MeQNO and 4-MeQNO] complexes have been prepared by the addition of L to aqueous solutions of Zeise's salt. 1H NMR and IR studies have been employed to compare the coordination ability of L and ethylene towards platinum metal. The reactions of [PtCl 2(C 2H 4)(4-MeQNO)] with L′ [L′ = CO, PPh 3, py(pyridine) and 4-NMe 2py] afforded the trans complexes [PtCl 2L′(4-MeQNO)], [PtCl 2L′ 2] and [PtCl 2(C 2H 4)(4-NMe 2py)]. Furthermore, the ability of [PtCl 2(C 2H 4)L] to react towards styrene resulted in the formation of five novel complexes of the type trans-[PtCl 2(styrene)L], which have been characterized by spectroscopic means ( 1H, 13C NMR and IR).