catena-Poly[[[(di-2-pyridylamine-κ²N²,N^2′)copper(II)]-μ-benzene-1,3-dicarboxylato-κ³O¹,O^1′:O³] monohydrate], a zigzag coordination polymer with strong π–π interactions

Abstract

The novel title coordination polymer, {[Cu(C(8)H(4)O(4))(C(10)H(9)N(3))]·H(2)O}(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 π-π 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.

Poly[[(μ4-benzene-1,3,5-tricarboxylato-κ4O1:O1′:O2:O3)bis(2,2-bipyridine-κ2N,N′)(μ2-hydroxido)dicopper(II)] trihydrate]

“…The oxygen atoms of a syn-anti triatomic carboxylate bridge occupy the apical positions of the two coordination spheres. These Cu-O distances are very close to those reported for [Cu 2 (µ 5 -btb)(µ-OH)(µ-H 2 O)] n (btb= benzene-1,2,3-tricarboxylate) (Janiak et al, 2008) and shorter than that (Rogan et al, 2011). The rest of the basal sites of each Cu II centre are occupied by a monodentate carboxylate oxygen of another BTC 3ligand, and completed by an N,N-chelating dipyridine ligand.…”

“…Additional short Cu1-O5 and Cu2-O7 contacts, 2.935 (2) and 2.866 (2) Å respectively, are almost equal or slightly shorter than the sum of the van der Waals radii ( 2.92 Å), and also slightly shorter than 3.0229Å ( Rogan et al, 2011).…”

“…For a coordination polymer containing benzenetricarboxlyate, see: Wang et al (2005). For Cu-O bond-length data, see: Janiak et al (2008); Rogan et al (2011). For related structures, see: Christou et al (1990); Tokii et al (1992).…”