Amide- and urea-functionalized dithienylethene: synthesis, photochromism, and binding with halide anions.

A versatile amide- and urea-functionalized dithienylethene has been successfully synthesized. Upon irradiation with UV or visible light, the compound showed excellent fatigue resistance. As a synthetic receptor, the dithienylethene displayed switchable affinities for Cl(-) and Br(-) anions when the UV/vis light was introduced. The switchable binding ability also had good reversibility.