Viologen-derived material showing photochromic, visually oxygen responsive, and photomodulated luminescence behaviors

Abstract

The synthesis of photochromic functional materials with excellent performances is important owing to their workable applications. In this study, a new viologen-derived Zn(II) material with a two-dimensional layered structure, namely {[Zn(L)(cpbpy)](H₂O)₃}_n (1; H₂L = 2,5-thiophenedicarboxylic acid; cpbpy = N-(3-carboxypyridin-5-yl)-4,4′-bipyridinium), was fabricated based on a new mono-substituted viologen derivative via a solvothermal synthesis. Similar to materials containing viologens, 1 displayed a photochromic behavior upon xenon light irradiation. Interestingly, its dehydrated product 1a exhibited a rapid photochromism only under vacuum or an inert atmosphere, which makes 1a a potential O₂ sensitive material. Further investigations show that 1 and 1a had remarkably different photomodulated luminescence behaviors. This study widens the application of such a viologen derivative towards constructing new photochromic materials having a rapid photochromic response.