title: Adiabatic versus nonadiabatic photoisomerization in photochromic ruthenium sulfoxide complexes: a mechanistic picture from density functional theory calculations.
abstract: Polypyridine ruthenium sulfoxide complexes are intriguing compounds which can display both photochromic and electrochromic properties. These properties are based on the Ru-S → Ru-O linkage isomerization capability of the sulfoxide group. The photoisomerization mechanism is of particular importance in order to understand the photophysical properties of such molecules. Density functional theory calculations demonstrate that the main photoisomerization mechanism is nonadiabatic for the system under study in agreement with the experimental observations. Indeed, funnels for efficient radiationless decay back to the ground state are shown to be easily accessible compared to transition states on the adiabatic triplet potential energy surface. However, we highlight for the first time that triplet metal-centered states play a central role in the photoisomerization mechanism of these compounds.
authors: Laboratoire de Chimie et Physique Quantiques-IRSAMC, CNRS et Université de Toulouse, 31062 Toulouse, France.
authors: Adrien J
authors: AJ
authors: Göttle
authors: Isabelle M
authors: IM
authors: Dixon
authors: Fabienne
authors: F
authors: Alary
authors: Jean-Louis
authors: JL
authors: Heully
authors: Martial
authors: M
authors: Boggio-Pasqua