Sanz García Juan, Alary Fabienne, Boggio-Pasqua Martial, Dixon Isabelle M, Malfant Isabelle, Heully Jean-Louis
Laboratoire de Chimie et Physique Quantiques, UMR 5626, IRSAMC, CNRS et Université de Toulouse , 118 route de Narbonne, 31062 Toulouse, France.
Laboratoire de Chimie de Coordination, CNRS UPR 8241 , 205 route de Narbonne, 31077 Toulouse, France.
Inorg Chem. 2015 Sep 8;54(17):8310-8. doi: 10.1021/acs.inorgchem.5b00998. Epub 2015 Aug 14.
The density functional theory calculations presented in this work allow the first rationalization of the full linkage photoisomerization mechanism of trans-RuCl(NO)(py)4, in both the forward and reverse directions. These mechanisms are consistent with the experimental data establishing that blue-light irradiation triggers the forward process, while red or IR photons trigger the reverse process. Characterization of the singlet and lowest triplet potential energy surfaces shows that, despite the unfavorable thermodynamic character of the forward process, the topologies of the surfaces and particularly some crucial surface crossings enable the isomerization. In the forward Ru-NO → Ru-ON direction, a sequential two-photon absorption mechanism is unraveled that involves a sideways-bonded metastable state. In contrast, in the reverse reaction, two mechanisms are proposed involving either one or two photons.
本工作中提出的密度泛函理论计算首次对反式-RuCl(NO)(py)₄的全键光异构化机理进行了合理解释，包括正向和反向过程。这些机理与实验数据一致，实验数据表明蓝光照射触发正向过程，而红光或红外光子触发反向过程。单重态和最低三重态势能面的表征表明，尽管正向过程具有不利的热力学特性，但表面的拓扑结构，特别是一些关键的表面交叉点使得异构化成为可能。在Ru-NO→Ru-ON的正向方向上，揭示了一种连续双光子吸收机制，该机制涉及一个侧向键合的亚稳态。相比之下，在反向反应中，提出了两种机制，涉及一个或两个光子。
