Solvothermal synthesis, crystal structure, and photocatalytic H 2 evolution of two Cu II coordination polymers based on Keggin polyoxotungstates

Two new Cu-II coordination polymers based on alpha-Keggin polyoxotungstates, [Cu-2(dpa)(2)(H2O)(2)(GeW12O40)]center dot 0.5CH(3)COOH (1) and [Hdpa][Cu-2(dpa)(2)(4,4'-bipy)(H2O)(2)(PW10V2O40)] (2) (dpa = 2,2'-dipyridylamine, 4,4'-bipy = 4,4'-bipyridine), were obtained by solvothermal reactions in glacial acetic acid and characterized by elemental analysis, IR spectroscopy, TG analysis, X-ray powder diffraction, and single-crystal X-ray diffraction. Compound 1 exhibits a ID two-rowed chain constructed from [GeW12O40](4-) anions coordinated with [Cu(1)(dpa)](2+) and [Cu(2)(dpa)(H2O)(2)](2+) fragments by four terminal oxygen atoms. Compound 2 exhibits a 2D layered structure constructed from [PW10V2O40](5-) anions coordinated with [Cu(dpa)(4,4'-bipy)(0.5)(H2O)](2+) fragments by four terminal oxygen atoms. Furthermore, the electrochemical properties of 1 and the photocatalytic hydrogen production of 1 and 2 were investigated.