catena-Poly[[[diaquacopper(II)]-μ-quinoline-2,3-dicarboxylato-κ3 N,O 2:O 3] monohydrate]

In the title compound, {[Cu(C11H5NO4)(H2O)2]·H2O}n, the CuII ion is five-coordinated by two O atoms and one N atom of two symmetry-related quinoline-2,3-dicarboxylate ligands, and two water molecules. The water molecules occupy basal and apical positions of the square-pyramidal coordination polyhedron. Each quinoline-2,3-dicarboxylate dianion bridges two adjacent CuII ions, forming a polymeric chain along [010]. The chains are further connected via O—H⋯O hydrogen-bonding interactions and quinoline ring π–π interactions [centroid–centroid distance = 3.725 (4) Å], generating a three-dimensional structure. Lattice water molecules participate in the crystal structure via O—H⋯O hydrogen bonds.


Experimental
All commercially obtained reagent grade chemicals were used without further purification. A mixture of copper chloride dihydrate (0.1708 g, 1 mmol) and 2,3-quinolinedicarboxylic acid (0.2171 g, 1 mmol) was added into 20 ml of water with few drops of ammonia solution, and then stirred for 1 h. After 2 days, blue crystals of the title complex were collected by filtration, washed with distilled water, and dried in air.

Refinement
All H atoms bonded to C atoms were positioned geometrically and refined using the riding model with C-H = 0.93 Å.
The H atoms of water molecules were located from a difference map and were restrained at distances O-H = 0.83 (1) Å.
The separation between H atoms in the same water molecule was restrained to H···H = 1.35 (1) Å. Cu and OW2 atoms were restrained to have similar displacement parameters (SIMU restraint; Sheldrick, 2008). Isotropic displacement parameters for H atoms were calculated as U iso (H) = 1.2U eq (carrier C) and U iso (H) = 1.5U eq (carrier O).

Figure 2
Crystal packing diagram for the title compound. All atoms are shown as isotropic spheres of arbitrary size. H atoms bonded to C atoms are omitted for clarity. The H-bonding interactions are shown as red dashed lines. -2,3-dicarboxylato-κ 3 N,O