THE ELECTRODE PROCESSES OF RU(III) THIOCYANATE COMPLEXES AT MERCURY AND PLATINUM-ELECTRODES

The process of Ru(III) thiocyanate complex electroreduction at mercury and platinum electrodes has been studied by voltammetry, chronoampero metry and polarography. The formation of two polarographic waves is ob served in the studied system. The first one is associated with the rev ersible one-electron reduction of the Ru(III)-SCN- complex. The formal potential of this process is equal to about -45 mV. At potentials mor e negative than about -800 mV the second wave related to the catalytic electroreduction of H+ ions is recorded. In the potential range of th is wave the formation of RuS has been observed. A detailed study of th e mechanism of this process shows that the chemical reduction of the R u(II)-SCN- complex by the atomic hydrogen adsorbed at the surface of t he electrode is responsible for the RuS formation. (C) 1997 Elsevier S cience S.A.