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

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.