Electrochemical Properties of Palladium and Platinum Phosphine Complexes

摘要

The electrochemistry of 11 palladium (II) and platinum (II) complexes of the type ML2X2(L = P, N, or C-donor; X = Cl or I) was examined by cyclic voltammetry in nonaqueous solution. Electrochemical reduction was irreversible and was coupled with loss of X(-). Equilibria between the metal complexes and added L significantly altered the observed electrochemistry. Reduction peak potentials for a homologous series of complexes qualitatively reflected expected ligand field strengths. Agreement was also found between the optical d-d transition energy and the electrochemical reduction potential for selected complexes. Trans-isomers were harder to reduce than cis-isomers by about 300 mV. A shift of approximately 400 mV to more negative potentials was determined for the reduction of Pt(II) for complexes with identical coordination environments. Saturation of the solution with carbon dioxide had no effect on the cyclic voltammetric behavior of the complexes.