catena-Poly[[[(di-2-pyridylamine-kappa N-2(2),N-2 ')copper(II)]-mu-benzene-1,3-dicarboxylato-kappa O-3(1),O-1 ':O-3] monohydrate], a zigzag coordination polymer with strong pi-pi interactions

Abstract

The novel title coordination polymer, {[Cu(C8H4O4)-(C10H9N3)]center dot H2O}(n), synthesized by the slow-diffusion method, takes the form of one-dimensional zigzag chains built up of Cu-II cations linked by benzene-1,3-dicarboxylate (ipht) anions. An exceptional characteristic of this structure is that it belongs to a small group of metal-organic polymers where ipht is coordinated as a bridging tridentate ligand with monodentate and chelate coordination of individual carboxylate groups. The Cu-II cation has a highly distorted square-pyramidal geometry formed by three O atoms from two ipht anions and two N atoms from a di-2-pyridylamine (dipya) ligand. The zigzag chains, which run along the b axis, further construct a three-dimensional metal-organic framework via strong face-to-face pi-pi interactions and hydrogen bonds. A solvent water molecule is linked to the different carboxylate groups via hydrogen bonds. Thermogravimetric and differential scanning calorimetric analyses confirm the strong hydrogen bonding.