Cyclometallated and cyclometalsilylated complexes of transition elements as photoredox sensitizers. Final report, January 1, 1988--September 30, 1996

摘要

The purpose of the research performed in this project was to explore the effects of metal-carbon and metal-silicon bonds upon excited states of transition metal complexes and to utilize these effects in the design of molecular species which would be useful in solar energy conversion processes. The initial phases of the research placed emphasis upon the use of ligands which bind transition metal ions such as Rh(III) and Ir(III) through an sp(sup 2) hybridized carbon atom while later stages of the research emphasized studies of complexes formed by binding of sp(sup 3) hybridized carbon or silicon atoms to the metal center. The rationale for the research was to enrich the electron density at the metal center to the point where the excited state might be useful as a powerful reducing agent which would have the capability of reducing carbon dioxide, either via direct outer sphere electron transfer to the carbon dioxide monoanion or through a catalytic inner sphere electron transfer cycle to produce reduced products in a catalytic manner which would regenerate the photoactive species.