title: Osmium(ii) complexes for light-driven aerobic oxidation of amines to imines.
abstract: Herein, we describe the synthesis and characterization of three Os(ii) complexes (i.e., [Os(fptz)2(PPhMe2)2] (1, fptzH = 3-trifluoromethyl-5-pyridyl-1,2,4-triazole), [Os(fptz)2(CO)(L1)] (2, L1 = PPh3; 3, L1 = pyridine)) that have been successfully utilized as good photocatalysts to promote aerobic oxidative coupling of amines to imines with molecular oxygen in air as a green oxidant. Complex 1 is the most effective catalyst for the oxidative coupling of benzylamine with molecular O2 (air) as the oxidant because of the complex's strong absorption of visible light and long-lived triplet state. The application of a low catalyst loading (0.06 mol%) of complex 1 to the oxidative coupling of a wide range of amines affords the corresponding imines efficiently and selectively in most cases. The reaction mechanism was investigated via relevant control and quenching experiments. The results indicated that the reaction occurs via an active (1)O2-involved pathway. The (1)O2-generating ability of complex 1 as a photosensitizer was evaluated using 9,10-dimethylanthracene (DMA) as a chemical trap for (1)O2.
authors.affiliation: National Laboratory of Solid State Microstructures and Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Nanjing University, Nanjing, Jiangsu 210093, P. R. China. yuzt@nju.edu.cn and Eco-Materials and Renewable Energy Research Center, College of Engineering and Applied Sciences, Nanjing University, and Kunshan Innovation Institute of Nanjing University, Nanjing, Jiangsu 210093, P. R. China.
authors.forename: Yong-Hui
authors.initials: YH
authors.lastname: Li
authors.affiliation: Department of Chemistry, Shantou University, Guangdong 515063, P. R. China.
authors.forename: Xiao-Le
authors.initials: XL
authors.lastname: Liu
authors.affiliation: National Laboratory of Solid State Microstructures and Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Nanjing University, Nanjing, Jiangsu 210093, P. R. China. yuzt@nju.edu.cn and Eco-Materials and Renewable Energy Research Center, College of Engineering and Applied Sciences, Nanjing University, and Kunshan Innovation Institute of Nanjing University, Nanjing, Jiangsu 210093, P. R. China.
authors.forename: Zhen-Tao
authors.initials: ZT
authors.lastname: Yu
authors.affiliation: National Laboratory of Solid State Microstructures and Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Nanjing University, Nanjing, Jiangsu 210093, P. R. China. yuzt@nju.edu.cn and Eco-Materials and Renewable Energy Research Center, College of Engineering and Applied Sciences, Nanjing University, and Kunshan Innovation Institute of Nanjing University, Nanjing, Jiangsu 210093, P. R. China.
authors.forename: Zhao-Sheng
authors.initials: ZS
authors.lastname: Li
authors.affiliation: National Laboratory of Solid State Microstructures and Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Nanjing University, Nanjing, Jiangsu 210093, P. R. China. yuzt@nju.edu.cn and Eco-Materials and Renewable Energy Research Center, College of Engineering and Applied Sciences, Nanjing University, and Kunshan Innovation Institute of Nanjing University, Nanjing, Jiangsu 210093, P. R. China.
authors.forename: Shi-Cheng
authors.initials: SC
authors.lastname: Yan
authors.affiliation: Department of Chemistry, Shantou University, Guangdong 515063, P. R. China.
authors.forename: Guang-Hui
authors.initials: GH
authors.lastname: Chen
authors.affiliation: National Laboratory of Solid State Microstructures and Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Nanjing University, Nanjing, Jiangsu 210093, P. R. China. yuzt@nju.edu.cn and Eco-Materials and Renewable Energy Research Center, College of Engineering and Applied Sciences, Nanjing University, and Kunshan Innovation Institute of Nanjing University, Nanjing, Jiangsu 210093, P. R. China.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Zou