Bipyridyltriazolium Chlorobismuthate with Thermo-/Photochromic and Photoluminescent Switching Behaviors Based on ET and CT†

Matched with 3,5-bis­(pyridine-2-yl)-1,2,4-triazole (2-bpt), a new electron donor–acceptor-based chlorobismuthate­(III) hybrid, [2-bpt]2[Bi2Cl10(H2O)]·5H2O was prepared solvothermally and characterized. The title compound (hydrated form) and its dehydrated form exhibit photo- and thermo-induced intermolecular electron transfer (ET), which correspond to dual ET photo/thermochromism for hydrated form, charge transfer thermochromism during dehydration, and simultaneously photoluminescent responses, respectively.