Poly[[diaqua[μ2-3-carboxy-5-(pyridine-4-carboxamido)benzoato][μ4-5-(pyridine-4-carboxamido)isophthalato]cerium(III)] monohydrate]

In the title compound, {[Ce(C14H9N2O5)(C14H8N2O5)(H2O)2]·H2O}n, three carboxyl groups of two independent isophthalate anions are deprotonated and they bridge the CeIII cations, forming a two-dimensional polymeric structure parallel to (001); another carboxyl group is not deprotonated and links with the adjacent pyridine ring via an O—H⋯N hydrogen bond. The CeIII cation is coordinated by six O atoms from carboxyl groups and two O atoms from coordinated water molecules in a distorted square-antiprismatic arrangement. Extensive O—H⋯O and O—H⋯N hydrogen bonding occurs in the crystal structure.

In the title compound, the central Ce III ion is eight-coordinated by two O atoms from two water molecules, two carboxylate O atoms from two partial-deprotonated HLligands and four other O atoms from four different L 2ligands, which forming a distorted square-antiprismatic geometry (Fig. 1). Moreover, the HLanions adopt µ 2 -η 1 :η 1 bridging coordination mode, while two carboxylate groups of each L 2ligand have different coordination modes, one is µ 2 -η 1 :η 1 bridging and the other one acts as µ 2 -η 2 :η 1 -bridging coordination mode, whereas the pyridyl group is free of coordination.
Such a coordination mode makes (I) into an infinite two-dimensional network (Fig. 2). The pyridyl groups are free.
Adjacent molecules are linked through O-H···N and O-H···O hydrogen bonds into a three-dimensional network.

Refinement
Amide H atoms were located in a difference Fourier map and refined as riding in as found relative positions, other H atoms were placed geometrically with O-H = 0.86 (water), 0.82 (carboxyl) and C-H = 0.93 Å), and refined in riding mode, U iso (H) = 1.2U eq (N,O,C).

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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.