TY - JOUR AU - Kuramochi, Yusuke AU - Ishitani, Osamu PY - 2019 M3 - Original Research TI - An Ir(III) Complex Photosensitizer With Strong Visible Light Absorption for Photocatalytic CO2 Reduction JO - Frontiers in Chemistry UR - https://www.frontiersin.org/articles/10.3389/fchem.2019.00259 VL - 7 SN - 2296-2646 N2 - A cyclometalated iridium(III) complex having 2-(pyren-1-yl)-4-methylquinoline ligands [Ir(pyr)] has a strong absorption band in the visible region (ε444nm = 67,000 M−1 cm−1) but does not act as a photosensitizer for photochemical reduction reactions in the presence of triethylamine as an electron donor. Here, 1,3-dimethyl-2-(o-hydroxyphenyl)-2,3-dihydro-1H-benzo[d]imidazole (BI(OH)H) was used instead of the amine, demonstrating that BI(OH)H efficiently quenched the excited state of Ir(pyr) and can undergo the photochemical carbon dioxide (CO2) reduction catalyzed by trans(Cl)-Ru(dmb)(CO)2Cl2 (dmb = 4,4′-dimethyl-2,2′-bipyridine, Ru) to produce formate as the main product. We also synthesized a binuclear complex combining Ir(pyr) and Ruvia an ethylene bridge and investigated its photochemical CO2 reduction activity in the presence of BI(OH)H. ER -