Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan.
J Am Chem Soc. 2012 Mar 14;134(10):4569-72. doi: 10.1021/ja300602h. Epub 2012 Mar 1.
Extensive efforts have been devoted to developing electron donor-acceptor systems that mimic the utilization of solar energy that occurs in photosynthesis. X-ray crystallographic analysis shows how absorbed photon energy is stabilized in those compounds by structural changes upon photoinduced electron transfer (ET). In this study, structural changes of a simple electron donor-acceptor dyad, 9-mesityl-10-methylacridinium cation (Acr(+)-Mes), upon photoinduced ET were directly observed by laser pump and X-ray probe crystallographic analysis. The N-methyl group in Acr(+) was bent, and a weak electrostatic interaction between Mes and a counteranion in the crystal (ClO(4)) was generated by photoinduced ET. These structural changes correspond to reduction and oxidation due to photoinduced ET and directly elucidate the mechanism in Acr(+)-Mes for mimicking photosynthesis efficiently.
人们投入了大量精力来开发电子给体-受体体系，以模拟光合作用中利用太阳能的过程。X 射线晶体学分析表明，在光诱导电子转移（ET）过程中，化合物的结构发生变化，从而稳定吸收的光子能量。在这项研究中，通过激光泵浦和 X 射线探针晶体学分析，直接观察到简单电子给体-受体二聚体 9-均三甲苯基-10-甲基吖啶鎓阳离子（Acr(+)-Mes）在光诱导 ET 时的结构变化。Acr(+)中的 N-甲基基团弯曲，光诱导 ET 产生了 Mes 与晶体中抗衡阴离子（ClO4-）之间的微弱静电相互作用。这些结构变化对应于光诱导 ET 引起的还原和氧化，并直接阐明了 Acr(+)-Mes 高效模拟光合作用的机制。
