Catalytic Hydrogenation of CO2 by Unsymmetric N−Heterocyclic Carbene−Nitrogen−Phosphine Ruthenium Complexes

Unsymmetric Ru-CNP and Ru-CN(H)P complexes are synthesized and applied in the hydrogenation of CO2 to formate for the first time. The Ru-CNP complex shows excellent stability and high activity. The TON is around 170 000 after 48 h at 200 °C, which is a relatively high record value among all the Ru complexes.