Preparation of a zwitterionic trichloroplatinum(II) complex with an alkylbipyridinum ligand and its reaction in dmso-d6 solution

A zwitterionic trichloroplatinum(II) complex PtCl3(4,4'-bpy-N-(n) stopBu) (1) was prepared by an aqueous reaction of [4,4'-bpy-N-Bu-n]Cl with K2PtCl4, and was characterized by (1) H-n.m.r. and IR spectroscopy as well as elemental analysis. Dissolving (1) into dmso-d (6) at 25 circle C yields a mixture of the complexes, cis-PtCl2(4,4'-bpy-N-n stopBu)(dmso-d (6)) (2-cis), trans-PtCl2(4,4'-bpy-N-nsupercript Bu)(dmso-d (6)) (2-trans), [4,4'-bpy-N-Bu-n]Cl and PtCl2(dmso-d (6))(2). Ratio of the products in the dmso-d (6) solution changed depending on the temperature and the total concentration of the complexes. These compounds are in equilibrium via isomerization reaction between (2-cis) and (2-trans) and via displacement reaction of the alkylbipyridinium ligand of (2-cis) and (2-trans) with dmso-d (6) to form [4,4'-bpy-N-(n) Bu]Cl and PtCl2(dmso-d (6))(2).