Light-driven catalytic hydrogenation of carbon dioxide at low-pressure by a trinuclear iridium polyhydride complex.

Low-pressure hydrogenation of carbon dioxide (CO2) has been achieved using a trinuclear iridium hexahydride complex 1. Complex 1 is ligated with a light-absorbing diphosphine ligand to induce light-sensitizing ability. Under photoirradiation, 1 catalyzes CO2 hydrogenation under low-pressure conditions (H2 (5 atm) and CO2 (5 atm)) and at ambient temperature to yield the corresponding formate in high yield.