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 (Zn-II for 1 and Mn-II for 2) is surrounded by four dci(-) ligands and two coordinated aqua in a distorted N4O2 octahedral geometry. The dci(-) anion adopts a new coordination mode of mu(2)-(N, N) through its neighbouring imidazole nitrogen and cyano nitrogen atoms, and connects adjacent metal ions together, thus forming the ID double-stranded chain structures 1 and 2. The solid-state fluorescence measurements for 1 and magnetic properties for 2 have been discussed. (C) 2011 Elsevier B.V. All rights reserved.