Photoinitiated long-lived charge separation with near-unity quantum yield in donor-acceptor1-acceptor2 systems for artificial photosynthesis
作者:Won-Sik Han、Brad S. Veldkamp、Scott M. Dyar、Samuel W. Eaton、Michael R. Wasielewski
DOI:10.1016/j.tet.2017.06.021
日期:2017.8
We report the synthesis and photophysical characterization of isomeric donor-acceptor1-acceptor2 (D-A1-A2) triads each comprising a perylene donor (D) connected by a xylene bridge to a naphthalene-1,8-dicarboximide primary acceptor (NMI, A1) that is, in turn, covalently linked to a naphthalene-1,4:5,8-bis(dicarboximide) secondary acceptor (NDI, A2) through a benzene ring at its ortho, meta or para
我们报告了合成和光物理特征的异构体供体-受体1-受体2(D - A 1 - A 2)三单元组,每个三联体包括二甲苯桥连接到萘-1,8-二甲酰亚胺主要受体的per供体(D) (NMI,A 1),然后通过苯环在邻位,间位或对位共价连接到萘-1,4:5,8-双(二甲叉酰亚胺)二级受体(NDI,A 2)(每xy-NMI- x-NDI)。Per的选择性光激发同时产生Per +•和NDI ‒•,在苯甲腈中的时间常数约为50 ps,在甲苯中的时间常数约为80 ps,产率> 98%。这比单步电子从1 * Per到NDI的转移要快得多,并且与两步机理一致,即1 * Per-Xy-NMI- x -NDI → Per +• -Xy-NMI ‒• - x -NDI →每+• -Xy-NMI- x -NDI ‒•,其中第二步比第一步快得多。另外,发现在这些系统中保持长寿命的电荷分离依赖于通过三重态自由基离子对重组途径抑制电荷重组。