CHEMICAL AND ELECTROCHEMICAL PROPERTIES OF 2,2'-BIPYRIDYL COMPLEXES OF RUTHENIUM COVALENTLY BOUND TO PLATINUM OXIDE ELECTRODES

The covalent attachment of 2, 2'-bipyridyl complexes of ruthenium to silanized platinum oxide electrodes by two different surface synthetic procedures is demonstrated. The electrodes, once prepared, show an impressive stability toward cycling between the ruthenium(II) and -(III) oxidation states. The surface-attached complexes largely retain the chemical characteristics exhibited by their homogeneous solution analogues, but a quenching of photochemical behavior is observed. Although stable indefinitely in the Ru(II) state, once oxidized to Ru(III), the surfaces undergo a slow decay process which results ultimately in the complete loss of ruthenium from the surface. The surface decay processes have been found to follow first-order kinetics. Current-potential wave shapes for the surface-bound Ru(III)/Ru(II) couples are treated in the light of surface activity parameters. © 1979, American Chemical Society. All rights reserved.