Ligand‐Assisted Electrochemical CO₂ Reduction by Ru‐Polypyridyl Complexes

The introduction of a simple triazole moiety on a terpyridine ligand in the complex [Ru(tpy)(bpy)(Cl)] + ([ 1 ] + ; tpy = 2,2':6',2''‐terpyridine; bpy = 2,2'‐bipyridine) gives rise to a suitable electrocatalyst for the reduction of CO 2 to CO. The triazole group in [Ru(tpyaz)(bpy)(Cl)] + {[ 2 ] + ; tpyaz = 4'‐[4‐( tert ‐butylphenyl)‐1 H ‐1,2,3‐triazol‐4‐yl]‐2,2':6',2''‐terpyridine} enables the complex [ 2 ] + to bind with CO 2 even at the one‐electron reduced state of the complex. Further 2 nd ‐electron addition after CO 2 ‐coordination to the catalyst facilitates efficient CO 2 reduction, based on cyclic voltammetry analysis.