Construction of three new mixed-ligand Zn(II) coordination polymers based on nitrogen-containing heterotopic ligands and carboxylate co-ligands

Abstract Reactions of Zn(II) salts, presynthesized 5-(4-(1H-imidazol-1-yl)phenyl)-1H-tetrazolate (HIPT) and various carboxylate ligands result to three new coordination polymers (CPs), namely, [Zn 2 [(IPT) 2 (ox)]} n (H 2 ox = oxalic acid, 1 ), [Zn 2 (IPT) 2 ( m NBDC)] n (H 2 m NBDC = 5-nitroisophthalic acid, 2 ), and [Zn 2 (IPT)(CA)(H 2 O)] n (H 3 CA = citric acid, 3 ). Compound 1 can be seen as constructed from 2D [Zn(IPT)] n layers with (6,3) topology and pillared by ox 2 − . It is a 3D (3,4)-connected framework with InS topology. Compound 2 has 2D bilayer structure based on 2D [Zn(IPT)] n single layer and m NBDC 2 − linkers. Compound 3 is a 3D pillar-layer framework built by Zn–CA bilayers and IPT − pillars. The results showed that the coordination modes, configurations of IPT − , and the structure of carboxylate co-ligands have great influence on the structures of the final network. The choice of carboxylate can decide the result of CPs in Zn–IPT chains/net subunits plus carboxyl linkers or Zn–carboxylate chains/net subunits plus IPT − linkers. The thermal stabilities and luminescent properties of selected compounds have also been studied.