Synthesis and characterization of Ag-ligand modified polyoxovanadates with three-dimensional structures

Two new coordination polymers {[Ag(bpe)]4V6O17}n (1) and {[Ag(bpe)]10V14O40}n∙3nH2O (2) (bpe = 1,2-di(4-pyridyl)ethylene) had been synthesized by hydrothermal methods, and characterized by elemental analysis, IR, UV–vis, TG, XRD and single-crystal X-ray diffraction. Structural analysis revealed that they both consist of {VO4}-based chain-like polyanions and {Ag-bpe} cationic units. The structural differences of 1–2 clearly showed that the polyoxovanadates are sensitive to the dosages of NH4VO3 source in synthesis reaction. The aromatic π…π stacking and Ag…Ag weak interactions among {Ag-bpe} cationic units contribute the significant effect on the stability of 3D crystal structures. The catalytic properties of the synthesized crystals were tested. It was found that the photochemical degradation of MB can reach 74.2% in 90 min by using 1 as catalyst.