Mechanistic studies of reactions of some platinum metal complexes

• Main Author: Vaughan, David Huw
• Published: Imperial College London 1968
• Subjects: 546
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.623155

The kinetics of the reactions of some anionic and cationic halogenoplatinate(IV) complexes with halide ions have been studied by spectrophotometric methods; the majority of the reactions were sufficiently fast to be followed using the stopped-flow technique. The reactions of trans- Pt(CN)4 X22- and trans- Pt0x2X22- (X = Cl, Br) with iodide are first order in both iodide and complex concentration and the mechanism probably involves a rate determining reduction of the Pt(IV) complex to Pt(II) followed by a fast reoxidation. The rates of the reactions appear to be related, in the majority of cases, to the thermodynamic ease of reduction, this indicates that both Pt-X bond breaking and X-I bond making play an important part in determining the rates of reaction. Several equilibrium constants for reduction of these complexes by iodide, bromide and chloride, as well as estimates of values for the replacement of chloride and bromide by iodide in trans- Pt(CN)4X22-, have been obtained.