Two coordination polymers induced by transition metal Zn(II) and Co(II) ions based on 3-nitrobenzene-1,2-dicarboxylic acid and 3,5-bis(1-imidazolyl)pyridine ligands

Abstract

Two new coordination polymers, {[Zn(3-Nbdc)(bip)]·2H2O}n (1) and {[Co(3-Nbdc)(bip)(H2O)]0.25H2O}n (2) (H23-Nbdc = 3-nitrobenzene-1,2-dicarboxylic acid, bip = 3,5-bis(1-imida­zolyl)pyridine) were synthesized under the hydrothermal conditions and characterized by single crystal X-ray diffraction and elemental analysis. In 1, the Zn(II) ion forms a slightly distorted [ZnO2N2] tetrahedron by two carboxylate oxygen atoms and two nitrogen atoms. Adjacent Zn(II) neighbors are linked by 3-Nbdc dianions adopting monodentate coordination mode to form 1D Zn-carboxylate chain, which is further extended by bip molecules to produce a two-dimensional thick layer. For complex 2, two six-coordinated Co(II) ions with different coordination environments are alternately connected by 3-Nbdc dianions and bip ligands along different directions to generate a two-dimensional grid layer. Furthermore, Powder X-ray diffractions, FTIR spectra and thermogravimetric analyses are also investigated.