Establishing the Two-Photon Linkage Isomerization Mechanism in the Nitrosyl Complex trans-[RuCl(NO)(py)4](2+) by DFT and TDDFT.
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](2+), 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.
Laboratoire de Chimie et Physique Quantiques, UMR 5626, IRSAMC, CNRS et Université de Toulouse , 118 route de Narbonne, 31062 Toulouse, France.
Juan
J
Sanz García
Laboratoire de Chimie et Physique Quantiques, UMR 5626, IRSAMC, CNRS et Université de Toulouse , 118 route de Narbonne, 31062 Toulouse, France.
Fabienne
F
Alary
Laboratoire de Chimie et Physique Quantiques, UMR 5626, IRSAMC, CNRS et Université de Toulouse , 118 route de Narbonne, 31062 Toulouse, France.
Martial
M
Boggio-Pasqua
Laboratoire de Chimie et Physique Quantiques, UMR 5626, IRSAMC, CNRS et Université de Toulouse , 118 route de Narbonne, 31062 Toulouse, France.
Isabelle M
IM
Dixon
Laboratoire de Chimie de Coordination, CNRS UPR 8241 , 205 route de Narbonne, 31077 Toulouse, France.
Isabelle
I
Malfant
Laboratoire de Chimie et Physique Quantiques, UMR 5626, IRSAMC, CNRS et Université de Toulouse , 118 route de Narbonne, 31062 Toulouse, France.
Jean-Louis
JL
Heully