Hydrothermal synthesis and structural characterization of a novel three-dimensional supramolecular framework constructed by zinc salt and pyridine-2,5-dicarboxylate

A novel metal-organic coordination polymer, [Zn(PDB)(H2O)2]4n (H2PDB ¼ pyridine-2,5-dicarboxylic acid), has been hydrothermally synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. Colorless crystals crystallized in the triclinic system, space group P-1, a ¼ 7:0562ð14Þ A ° , b ¼ 7:38526ð15Þ A ° , c ¼ 18:4611ð4Þ A ° , a ¼ 90:01ð3Þ8, b ¼ 96:98ð3Þ8, g ¼ 115:67ð3Þ8, V ¼ 859:1ð3Þ A° 3, Z ¼ 1 and R ¼ 0:0334: The structure of the compound exhibits a novel three-dimensional supramolecular network, mainly based on multipoint hydrogen bonds originated from within and outside of a large 24-membered ring. Interestingly, the threedimensional network consists of one-dimensional parallelogrammic channels in which coordinated water molecules point into the channel wall. q 2004 Elsevier B.V. All rights reserved.