Structure refinement and photocatalytic properties of porous POMCPs by selecting the isomerous PYTTZ

Abstract

Two polyoxometalate-based coordination polymers (POMCPs) constructed form Keggin POMs and Ag⁺ with pyttz were synthesized: [Ag₄(H₂pyttz-I)(H₂pyttz-II)(Hpyttz-II)][HSiW₁₂O₄₀]·4H₂O (1) and [Ag₄(H₂pyttz-II)(Hpyttz-II)₂][H₂SiW₁₂O₄₀]·3H₂O (2) (H₂pyttz-I = 3-(pyrid-2-yl)-5-(1H-1,2,4-triazol-3-yl)-1,2,4-triazolyl; H₂pyttz-II = 3-(pyrid-4-yl)-5-(1H-1,2,4-triazol-3-yl)-1,2,4-triazolyl). Both compounds have similar building units, similar stick-like units and similar 1D inorganic chains, but finally form the different motifs of tunnels (tunnel A in 1 and tunnel A&B in 2). By careful inspection of the structures of 1 and 2, it is believed that the isomerous pyttz molecules can precisely refine the structure of porous POMCPs without changing the underlying framework, which favors the study of the structure–activity relationship of POMCPs. Furthermore, the results of the photocatalytic activities show that compound 2 exhibits higher photocatalytic activity than that of compound 1, which is consistent with their structural characterization.