Synthesis of Two Coordination Polymer Photocatalysts and Significant Enhancement of Their Catalytic Photodegradation Activity by Doping with Co2+ Ions

The coordination polymers (CPs) [Zn-2(tipm)(1,3-BDC)(2)] (1) and [Co-2(tipm)(1,3-BDC)(2)]0.5CH(3)CN (20.5CH(3)CN) were synthesized by the reactions of Zn(NO3)(2) or Co(NO3)(2) with tetrakis[4-(1-imidazolyl)phenyl]methane (tipm) and benzene-1,3-dicarboxylic acid (1,3-H2BDC) under solvothermal conditions. Compounds 1 and 2 are isostructural and possess complicated three-dimensional frameworks with the Schlafli symbol (47(2))(6(2)7(3)12)(46(2)7(3)). Cobalt ions were incorporated into the Zn-based CP framework 1 during solvothermal crystallization to yield [Zn(2-2x)Co2x(tipm)(1,3-BDC)(2)]bH(2)O (x = 2.4%, b = 0 for 1a, x = 23%, b = 1 for 2aH(2)O). Doped CPs 1a and 2aH(2)O exhibited greater catalytic photodegradation of the dye rhodamine B (RhB) than the undoped complexes 1 and 2 and many literature examples.