Miliutina Elena, Guselnikova Olga, Soldatova Natalia S, Bainova Polina, Elashnikov Roman, Fitl Přemysl, Kurten Theo, Yusubov Mekhman S, Švorčík Václav, Valiev Rashid R, Chehimi Mohamed M, Lyutakov Oleksiy, Postnikov Pavel S
Research School of Chemistry & Applied Biomedical Sciences, National Research Tomsk Polytechnic University, Lenin Avenue 30, Tomsk 634050, Russia.
Institute of Chemical Technology, Technicka 5, Prague 16628, Czech Republic.
J Phys Chem Lett. 2020 Jul 16;11(14):5770-5776. doi: 10.1021/acs.jpclett.0c01350. Epub 2020 Jul 7.
Plasmon-assisted transformations of organic compounds represent a novel opportunity for conversion of light to chemical energy at room temperature. However, the mechanistic insights of interaction between plasmon energy and organic molecules is still under debate. Herein, we proposed a comprehensive study of the plasmon-assisted reaction mechanism using unsymmetric iodonium salts (ISs) as an organic probe. The experimental and theoretical analysis allow us to exclude the possible thermal effect or hot electron transfer. We found that plasmon interaction with unsymmetrical ISs led to the intramolecular excitation of electron followed by the regioselective cleavage of C-I bond with the formation of electron-rich radical species, which cannot be explained by the hot electron excitation or thermal effects. The high regioselectivity is explained by the direct excitation of electron to LUMO with the formation of a dissociative excited state according to quantum-chemical modeling, which provides novel opportunities for the fine control of reactivity using plasmon energy.
等离子体辅助的有机化合物转化为在室温下将光能转化为化学能提供了一个新的契机。然而，等离子体能量与有机分子之间相互作用的机理仍存在争议。在此，我们提出了一项以不对称碘鎓盐（ISs）作为有机探针，对等离子体辅助反应机理进行的全面研究。实验和理论分析使我们能够排除可能的热效应或热电子转移。我们发现，等离子体与不对称ISs的相互作用导致分子内电子激发，随后C-I键发生区域选择性裂解，形成富电子自由基物种，这无法用热电子激发或热效应来解释。根据量子化学模型，通过电子直接激发到最低未占分子轨道并形成解离激发态来解释这种高区域选择性，这为利用等离子体能量精细控制反应活性提供了新的契机。
