Highly Functional Dinuclear CuI-Complex Photosensitizers for Photocatalytic CO2 Reduction

Two dinuclear Cu-I complexes with two tetradentate ligands consisting of a diimine unit and two diphenylphosphine units connected with -C4H8- chains were synthesized. The Cu-I dimer with p-CF3 substituents worked as an outstanding redox photosensitizer for photocatalytic CO2 reduction; Fe-II(dmp)(2)(NCS)(2) (dmp = 2,9-dimethyl-1,10-phenanthroline) was used as a catalyst, and CO was produced with a quantum yield of 14.1%. This is one of the most efficient photocatalytic systems using only abundant elements. This Cu dimer was significantly durable: approximately 80% remained in the reaction solution after irradiation for 48 h, while the turnover number was TONCO = 778 based on the dinuclear CuI complex used.

Automated summary

Two dinuclear Cu(I) complexes were synthesized, with one showing outstanding redox photosensitizing properties for photocatalytic CO2 reduction. A Fe(II) complex was used as the catalyst, resulting in a 14.1% quantum yield of CO production. The Cu dimer displayed significant durability and a high turnover number in the reaction.