Bigger is not Better for Indolino‐Oxazoline Photochemical Properties

Indolino‐oxazolidine derivatives are a new and pretty confidential family of multimodal molecular switches. Indeed, acid, electrochemical potential, and UV light irradiation can be used to convert these compounds form their colorless closed form to a colorful open form. In this publication, we have investigated the influence of the extension of the π‐conjugated system beared by the indolino moiety on their halo‐, electro‐ and photochromic properties. In this context, we have demonstrated that only their photochemical properties are strongly affected by this structural modification. Moreover, quantum chemistry calculations have allowed to rationalize our experimental observations and, noticeably, evidenced an oxidative quenching process in presence of chlorobenzene, which enhances their photoreactivity. The influence of the elongation of the pi conjugated system on the multimodal switching abilities of Benzazolo‐Oxazolidine unit has been studied experimentally and rationalized by quantum calculations. The halochromic and electrochromic properties are poorly impacted by this structural modification. At the opposite, the extension of the pi conjugated system conducts to observe a reduction of their photochemical reactivity.