Photochromic properties of a dithienylethene-indolinooxazolidine switch: A theoretical investigation

Using ab initio spectroscopic tools, we have studied the structural and electronic properties of an hybrid dithienylethene-indolinooxazolidine switch synthesized by Pozzo and coworkers [Photochem. Photobiol. Sci. 9 (2010) 131]. To simulate the electronic absorption spectra of this mixed photochrome, we relied on a PCM-TD-DFT approach. Several functionals have been considered, namely the PBE0 global hybrid as well as four range-separated hybrids (CAM-B3LYP, LC-ωPBE, ωB97X and ωB97XD). On average, considering all four closed/open structures, ωB97XD provides the best compromise for estimating the transition wavelengths. It is shown that the TD-DFT procedure combined with an analysis of the molecular orbitals implied in the absorption bands provide insights into the observed photochromic pathways.