Development of a panchromatic photosensitizer and its application to photocatalytic CO2 reduction. Issue 41 (6th October 2021)

• Record Type: Journal Article
• Authors: Irikura, Mari; Tamaki, Yusuke; Ishitani, Osamu
• Is Part Of: Chemical science. Volume 12:Issue 41(2021)
• Page Start: 13888
• Page End: 13896
• Publication Date: 2021-10-06
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d1sc04045f
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : The osmium(ii ) complex functioned as a panchromatic photosensitizer and drove CO2 reduction. Abstract : We designed and synthesized a heteroleptic osmium(ii ) complex with two different tridentate ligands, Os . Os can absorb the full wavelength range of visible light owing to S–T transitions, and this was supported by TD-DFT calculations. Excitation of Os using visible light of any wavelength generates the same lowest triplet metal-to-ligand charge-transfer excited state, the lifetime of which is relatively long ( τ em = 40 ns). Since excited Os could be reductively quenched by 1, 3-dimethyl-2-( o -hydroxyphenyl)-2, 3-dihydro-1 H -benzo[ d ]imidazole, Os displays high potential as a panchromatic photosensitizer. Using a combination of Os and a ruthenium(ii ) catalyst, CO2 was photocatalytically reduced to HCOOH via irradiation with 725 nm light, and the turnover number reached 81; irradiation with light at λ ex > 770 nm also photocatalytically induced HCOOH formation. These results clearly indicate that Os can function as a panchromatic redox photosensitizer.