A Novel MOF Based on a Viologen Ligand: Photochromism, Ammonia Sensing, and Cr2O72− Detection

Abstract A novel metal‐organic frameworks (MOF) material, namely {Zn 3 (bpybc)(imdc) 2 ·H 2 O)} n ( 1 ), (bpybc 2− = 1,1′‐bis(4‐carboxyphenyl)‐4,4′ ‐bipyridinium cation, imdc 3− = 4,5‐imidazole‐dicarboxylic acid anion) has been successfully synthesized under solvothermal conditions. The synthesis utilized H 2 bpybc·2Cl, 4,5‐imidazole‐dicarboxylic acid and Zn(NO 3 ) 2 ·6H 2 O as the raw materials. Complex 1 not only exhibits reversible photochromic behavior but also features photocontrolled luminescence properties. Notably, complex 1 shows the sensing ability of Cr 2 O 7 2− . It has the capability to selectively detect ammonia vapor, undergoing a color change from orange to tan in response to ammonia vapors, thereby exhibiting certain sensing properties for ammonia vapor.