Electrochemistry and catalytic behavior of immobilized binuclear complexes of copper(II) and nickel(II) with Robson type ligand

Various systems containing immobilized binuclear copper(II) and nickel(II) complexes with Robson type ligand ([M2L]Cl2) are studied and compared in relation to catalysis of hydrogen peroxide reduction. Molecular complexes adsorbed on mercury and gold, crystalline complexes immobilized in the carbon paste electrode, and complex species entrapped into polyphenol-modified gold electrodes are considered. Electrocatalysis is assumed to result from the formation of H2O2–[M2L]Cl2 adduct, not from mediating redox transformations. Possible geometry of the formed reaction layers supporting adduct formation is discussed.