Zinc and manganese coordination polymers constructed by a new coordination mode of 4, 5-dicyanoimidazolate ligand: Syntheses, crystal structures, fluorescent and magnetic properties

Two isostructural coordination polymers, [Zn(dci)2(H2O)2]n (1) and [Mn(dci)2(H2O)2]n (2) (Hdci = 4, 5-dicyanoimidazole), have been synthesized by conventional solution reactions and characterized by IR spectra, elemental analyses and single-crystal X-ray diffractions. In both complexes, the metal ion (ZnII for 1 and MnII for 2) is surrounded by four dciˉ ligands and two coordinated aqua in a distorted N4O2 octahedral geometry. The dciˉ anion adopts a new coordination mode of μ2-(N, Nʺ) through its neighbouring imidazole nitrogen and cyano nitrogen atoms, and connects adjacent metal ions together, thus forming the 1D double-stranded chain structures 1 and 2. The solid-state fluorescence measurements for 1 and magnetic properties for 2 have been discussed.