Chen Kai-Kai, Guo Song, Liu Heyuan, Li Xiyou, Zhang Zhi-Ming, Lu Tong-Bu
MOE International Joint Laboratory of Materials Microstructure, Institute for New Energy Materials and Low Carbon Technologies, School of Materials Science & Engineering, Tianjin University of Technology, Tianjin, 300384, China.
School of Materials Science and Engineering, College of New Energy, China University of Petroleum (East China), Qingdao, Shandong, 266580, China.
Angew Chem Int Ed Engl. 2020 Jul 27;59(31):12951-12957. doi: 10.1002/anie.202003251. Epub 2020 May 20.
Developing strong visible-light-absorbing (SVLA) earth-abundant photosensitizers (PSs) for significantly improving the utilization of solar energy is highly desirable, yet it remains a great challenge. Herein, we adopt a through-bond energy transfer (TBET) strategy by bridging boron dipyrromethene (Bodipy) and a Cu complex with an electronically conjugated bridge, resulting in the first SVLA Cu PSs (Cu-2 and Cu-3). Cu-3 has an extremely high molar extinction coefficient of 162 260 m cm at 518 nm, over 62 times higher than that of traditional Cu PS (Cu-1). The photooxidation activity of Cu-3 is much greater than that of Cu-1 and noble-metal PSs (Ru(bpy) and Ir(ppy) ) for both energy- and electron-transfer reactions. Femto- and nanosecond transient absorption and theoretical investigations demonstrate that a "ping-pong" energy-transfer process in Cu-3 involving a forward singlet TBET from Bodipy to the Cu complex and a backward triplet-triplet energy transfer greatly contribute to the long-lived and Bodipy-localized triplet excited state.
开发用于显著提高太阳能利用率的强可见光吸收（SVLA）且储量丰富的地球光敏剂（PSs）非常有必要，但这仍然是一个巨大的挑战。在此，我们采用通过键能转移（TBET）策略，通过一个电子共轭桥将硼二吡咯亚甲基（Bodipy）和一个铜配合物连接起来，从而得到首个SVLA铜光敏剂（Cu-2和Cu-3）。Cu-3在518 nm处具有162 260 m cm的极高摩尔消光系数，比传统铜光敏剂（Cu-1）高62倍以上。对于能量转移和电子转移反应，Cu-3的光氧化活性远大于Cu-1和贵金属光敏剂（Ru(bpy) 和Ir(ppy) ）。飞秒和纳秒瞬态吸收以及理论研究表明，Cu-3中的“乒乓”能量转移过程涉及从Bodipy到铜配合物的正向单重态TBET和反向三重态-三重态能量转移，这极大地促成了长寿命且Bodipy定位的三重态激发态。
