Electrochemistry and Spectroelectrochemistry of Chloro(phthalocyaninato)Rhodium(III) Species in Solution Phase

Abstract

The electrochemistry and spectroelectrochemistry of mononuclear chloro(phthalocyaninato)rhodium(III), ClRhIIIPc, has been studied in the solution phase, at ambient and low temperature. Reduction leads to a rhodium(II) species, ClRhIIPc which is stable at low temperature, with reversible electrochemistry, but at ambient temperature dimerizes generating a rhodium−rhodium-bonded dinuclear species. This dinuclear species is oxidized at a much more positive potential than the mononuclear species. The complex electrochemical behavior of these species is shown to be due to the presence of three different dinuclear RhII species with zero, one, or two axially bound chloride ions whose detailed electrochemical properties are explored. Reduction of the dinuclear RhIIPc species leads to a reversibly generated anion radical species.