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

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 O-2 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.