Photocatalytic reduction of CO₂ using cis,trans-[Re(dmbpy)(CO)₂(PR₃)(PR’₃)]⁺ (dmbpy=4,4′-dimethyl-2,2′-bipyridine)

Photocatalysis of biscarbonylrhenium complexes cis,trans-[Re(dmbpy)(CO)(2)(PR3) (PR3')](+) (dmbpy = 4,4'-dimethyl-2,2'-bipyridine: R,R' = Ph (1a(+)); p-FPh (1b(+)); R = Ph, R' OEt (1c(+)); R,R' = O-i-Pr (1d(+))) is reported for the first time. The rhenium complexes with two triarylphosphine ligands (1a(+), 1b(+)) efficiently photocatalyzed CO2 reduction with triethanolamine as a sacrificial donor. On the other hand, the complexes with one or two trialkylphosphite ligand(s) (1c(+), 1d(+)) had low photocatalytic abilities under the same reaction conditions.