Photocatalytic function of the B-12 complex with the cyclometalated iridium(III) complex as a photosensitizer under visible light irradiation
- 주제(기타) Chemistry, Inorganic & Nuclear
- 설명문(일반) [Tian, Hui; Shimakoshi, Hisashi; Hisaeda, Yoshio] Kyushu Univ, Grad Sch Engn, Dept Chem & Biochem, Fukuoka 8190395, Japan; [Park, Gyurim; Kim, Sinheui; You, Youngmin] Ewha Womans Univ, Div Chem Engn & Mat Sci, Seoul 03760, South Korea
- 관리정보기술 faculty
- 등재 SCIE, SCOPUS
- 발행기관 ROYAL SOC CHEMISTRY
- 발행년도 2018
- URI http://www.dcollection.net/handler/ewha/000000150056
- 본문언어 영어
- Published As http://dx.doi.org/10.1039/c7dt03742b
초록/요약
A visible light induced three-component catalytic system with the cobalamin derivative (B-12) as a catalyst, the cyclometalated iridium(III) complex (Irdfppy, Irppy, Irpbt and [Ir{dF(CF3)ppy}(2)(dtbpy)]PF6) as a photosensitizer and triethanolamine as an electron source under N-2 was developed. This catalytic system showed a much higher catalytic efficiency than the previous catalytic system using [Ru(II)(bpy)(3)]Cl-2 as the photosensitizer for the dechlorination reaction of 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT). Noteworthy is the fact that the remarkable high turnover number (over ten thousand) based on B-12, which ranks at the top among the reported studies, was obtained when Irdfppy was used as a photosensitizer. This photocatalytic system was also successfully applied to the B-12 enzyme-mimic reaction, i.e., the 1,2-migration of the phenyl group of 2-bromomethyl-2-phenylmalonate. The plausible reaction mechanism was proposed, which involved two quenching pathways, an oxidative quenching pathway and a reductive quenching pathway, to be responsible for the initial electron transfer of the excited-state photosensitizers during the DDT dechlorination reaction. Transient photoluminescence experiments revealed that the oxidative quenching of the photosensitizer dominated over the reductive quenching pathway.
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