Two Interpenetrated Zn(II) Coordination Polymers: Synthesis, Topological Structures, and Property

Two interpenetrated coordination polymers (CPs) {[Zn1(L)(NO2pbda)]n[Zn2(L)(NO2pbda)]n} (1) and [Zn(L)(Brpbda)]n (2) were prepared by reactions of zinc sulfate heptahydrate with N-donor ligands of 1,4-di(1H-imidazol-4-yl)benzene (L) and auxiliary carboxylic acids of nitroterephthalic acid (H2NO2pbda) and 2,5-dibromoterephthalic acid (H2Brpbda), respectively. The structures of the CPs were characterized by Fourier-Transform Infrared (IR) spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The coordination polymer 1 has two different (4, 4) sql 2D layer structures based on the [Zn(L)(NO2pbda)] moiety, which results in inclined interpenetration with a 2D + 2D → 3D architecture, while the CP 2 exhibits a 3-fold interpenetrating dmp network. The diffuse reflectance spectra are also investigated for the CPs 1 and 2.