Monica R Madsen, Joakim B Jakobsen, Magnus H Rønne, Hongqing Liang, Hans Christian D Hammershøj, Peter Nørby, Steen U Pedersen, Troels Skrydstrup, Kim Daasbjerg

https://doi.org/10.1021/acs.organomet.9b00815

Carbon dioxide utilization through electrocatalysis is a promising pathway toward a more sustainable future. In this work the electrocatalytic reduction of carbon dioxide by Re^I and Ru^IIbipyridine complexes bearing pendant amines (N,N′-(([2,2′-bipyridine]-6,6′-diylbis(2,1-phenylene))bis(methylene))bis(N-ethylethanamine) (dEAbpy)) is evaluated. In both cases, the major reduction product is carbon monoxide accompanied by some formic acid, although the yield of the latter never reaches the predominant level known from the corresponding Mn(dEAbpy)(CO)₃Br complex. This demonstrates the profound effect of the identity of the metal center, in addition to the ligand, for the product distribution. In this work, we report the synthesis procedures and X-ray diffraction studies along with electrochemical and infrared spectroelectrochemical studies of Re(dEAbpy)(CO)₃Cl and Ru(dEAbpy)(CO)₂Cl₂ to propose a mechanism for the CO₂ reduction reaction.