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

Highlights: • Two new coordination polymers have been synthesized and characterized. • The structures of crystals are stabilized by weak π…π and Ag…Ag interactions. • The formation of V-O clusters is senstitive to the reaction condition. -- Abstract: 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.