Photo‐electrochromic salt composed by viologen cation and diarylethene anion derivatives.

A multi‐responsive photo and electrochromic salt based on a viologen derivative ([(C10)2Bpy]2+) as organic cation combined with diarylethene anion ([DTE]2−) is synthesized and characterized for the first time. The coloration of this functional salt can be modulated by light and electricity according to further applications. Photochemical determination of the quantum yields in solution for the ring‐opening and closure of [(C10)2Bpy][DTE‐COO] ionic liquid have been determined. The electrochemical and electrochromism performance have been also studied in order to evaluate the reduction of bipyridinium cation as well as the oxidation of the DTE anion in its open and closed forms. The possibility of individually addressing the redox state of the anion and cation is seen as a very attractive approach to designing photo‐electrochromic devices. [ABSTRACT FROM AUTHOR]