Competitive (13)C and (18)O kinetic isotope effects on CO2 reduction catalyzed by Re(bpy)(CO)3Cl.

Competitive (13)C and (18)O kinetic isotope effects (KIEs) on CO2 reduction catalyzed by Re(bpy)(CO)3Cl () under photocatalytic conditions and using Na(Hg) amalgam as a sacrificial reducing agent are reported. The analysis of the measured KIEs rules out the outer-sphere electron transfer mechanism and indicates that CO2 binding to the reduced rhenium complex is the rate determining step in the reduction of CO2 by under these conditions.