Copper(ii) coordination polymers: tunable structures and a different activation effect of hydrogen peroxide for the degradation of methyl orange under visible light irradiation

Abstract

By tuning the synthesis conditions, based on a conformation-sensitive ligand, 1,4-bis(1,2,4-triazole-1-methylene)-2,3,5,6-tetramethyl benzene (btmx) and Cu(NO₃)₂·3H₂O/CuCl₂·2H₂O, we have obtained three Cu(II) coordination polymers with diverse structures, namely, {[Cu(btmx)₂(H₂O)]·2NO₃}_n (1), {[Cu(btmx)₂(Cl)₂]·5H₂O}_n (2) and [Cu(btmx)(Cl)₂]_n (3). Complex 1 exhibits a novel 2D → 3D interpenetrating structure with a point symbol of 6³. Complex 2 features an irregular 2D grid with (4⁴·6²) topology. The structure of complex 3 is a 1D double chain structure. The ultraviolet-visible absorption spectra and TG curves of these complexes are also presented and discussed. Moreover, under visible light, the coordination polymers 1, 2, and 3 display a different activation effect of hydrogen peroxide (H₂O₂) for the photocatalytic decomposition of methyl orange (MO), which indicates that the coordination polymers may have bright prospects in the field of photocatalytic degradation of dyes.