Crystal structure of poly[dichlorido(μ-2,5-dicarboxybenzene-1,4-dicarboxylato-κ2 O 1:O 4)bis[μ-4′-(pyridin-3-yl)-4,2′:6′,4′′-terpyridine-κ2 N 1:N 4′]dizinc]

Both the 2,5-dicarboxybenzene-1,4-dicarboxylate dianions and pyridyl-terpyridine ligands bridge the ZnII atoms, forming a ladder-like polymeric complex.


Chemical context
Coordination polymers (CPs) represent a class of crystalline materials which consist of different ligands interconnected by metallic nodes (Yaghi & Li;1995;Hinterholzinger et al., 2012). Compared to traditional inorganic materials, CPs have fascinating structures with regular pore shape and size obtained by rational design (Kepert, 2006;Brammer, 2004). In addition, studies over several decades have revealed that CPs have multi-functional applications such as gas storage and separation (Rosi et al., 2003;Jiang et al., 2013), chemical purification (Li et al., 2012), catalysis (Seo et al., 2000), and sensors (Kreno et al., 2012), etc.

Supramolecular features
In the crystal, classical O-HÁ Á ÁN hydrogen bonds, weak C-HÁ Á ÁO and C-HÁ Á ÁCl hydrogen bonds (Table 1) link the chains into a three-dimensional supramolecular architecture.
stacking is observed between the N3-pyridine ring and benzene ring of the neighboring chain, with a centroid-tocentroid distance of 3.7280 (14) Å .

Figure 2
Part of the polymeric chain.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.