Synthesis and kinetic studies of new bipyridyl platinum(II) phenoxide complexes by phase transfer catalysis: Crystal structure of [(bipy)Pt(OC6H4-4-OMe)2

Abstract

Abstract The synthesis of new platinum bipy (bipy = 2,2′-bipyridyl) complexes containing phenoxide ligands is reported, together with kinetic studies of their oxidative addition reactions with MeI to produce phenoxo platinum(IV) complexes. Complexes of the form [(bipy)Pt(OC 6 H 4 -4-X) 2 ] (X = OCH 3 , CH 3 , H, Br, Cl) are prepared by the reaction of the chloro complex [(bipy)PtCl 2 ] with substituted phenols and KOH in a two phase system of water and chloroform in the presence of benzyl triphenylphosphonium chloride. Platinum(IV) complexes are formed by oxidative addition of MeI to the platinum(II) complexes obtained. The complexes are characterized by elemental analysis, UV–Vis, IR, mass spectrometry and 1 H and 13 C NMR spectroscopy. The reaction of methyl iodide with [(bipy)Pt(OC 6 H 4 -4-OMe) 2 ] to give [(bipy)PtMe(I)(OC 6 H 4 -4-OMe) 2 ] follows the rate law rate = k 2 [(bipy)Pt(OC 6 H 4 -4-OMe) 2 ][MeI]. The values of k 2 increase with increasing polarity of the solvent, suggesting a polar transition state for the reaction.