Synthesis, structures and thermal stabilities of five copper(II) coordination polymers based on 2,4,6-tris(pyridyl)-1,3,5-triazine and 1,2,4,5-benzenetetracarboxylate ligands

Hydrothermal reactions of Cu(II) salts with 2,4,6-tris(3/4-pyridyl)-1,3,5-triazine (3/4-tpt) and 1,2,4,5-benzenetetracarboxylic acid (H(4)btec) afforded five novel coordination polymers, namely [Cu-4(3-tpt)(2)(btec)(2)(H2O)(4)](n)center dot 6nH(2)O (1), [Cu(3-tpt)(2)(H(2)btec)](n) (2), [Cu-3(3-Htpt)(2)(H(2)btec)(2)(btec)](n)center dot 4nH(2)O (3), [Cu-2(4-tpt)(3)(H(2)btec)(2)](n)center dot 4nH(2)O (4), and [Cu-3(4-tpt)(2)(Hbtec)(2)(H2O)](n)center dot 3nH(2)O (5). These complexes exhibit various polymeric networks due to diverse coordination modes of tpt and H(4)btec. Complex 1 displays a 3-D metal-organic framework in which 3-tpt is an exo-tridentate ligand and mu(4)-btec(4) coordinates to two square-pyramidal Cu(II) and two square Cu(II) ions. Complex 2 is a 1-D chain coordination polymer which contains mu(2)-H(2)btec(2) bridge and monodentate 3-tpt. Complex 3 shows a 3-D metal-organic framework constructed from protonated bidentate 3-Htpt(+), tridentate H(2)btec(2) and tetradentate btec(4). Complex 4 is a 1-D ladder-like coordination polymer assembled by mu(2)-H(2)btec(2) , mono-and bidentate 4-tpt. Complex 5 exhibits a porous 3-D metal-organic framework constructing from tridentate 4-tpt and mu(3)-Hbtec(3). Their thermal stabilities were also investigated. (C) 2009 Elsevier B. V. All rights reserved.