Syntheses and structural characterization of two zinc coordination polymers composed of polycarboxylate and N-donor ligands

Abstract

Two zinc coordination polymers with the formulas [Zn(btec)0.5(L1)]n (1) and [Zn(4-npa)(L2)]n (2) ((L1 = bis(4-(1H-imidazol-1-yl)phenyl)methanone, L2 = bis(4-(1H-benzo[d]imidazol-1-yl)phenyl)methanone, 4-H2npa = 4-nitrophthalic acid, H4btec = 1,2,4,5-benzenetetracarboxylic acid) are synthesized and structurally characterized. The single crystal X-ray diffraction analysis shows that Zn1 in 1 is four-coordinated by two carboxylate oxygen atoms of two different betc4– ligands in a μ1-η1:η0 monodentate coordination mode and two nitrogen atoms from two L1 ligands to give a slightly distorted tetrahedral coordination geometry. The complex possesses a 4-connected net topology with the point symbol {65·8}. In 2, Zn1 has a distorted tetrahedral geometry with two O atoms from two 4-npa2– ligands and two N atoms from two L2 ligands. The [Zn(4-npa)]2 units are linked with each other by the L2 ligands to form a 2D network.