Crystal structure of a heterometallic coordination polymer: catena -poly[[[tetraaquacobalt(II)]-μ-pyridine-2,6-dicarboxylato-calcium(II)-μ-pyridine-2,6-dicarboxylato] dihydrate]

In the crystal of the title polymeric complex, {[CoCa(C 7 H 3 NO 4 ) 2 (H 2 O) 4 ]·2H 2 O} n ( 1 ), the Co II ion is N , O , O ′-chelated by two pyridine-2,6-dicarboxylate anions in a distorted N 2 O 4 octahedral geometry, and two carboxylate O atoms of pyridine-2,6-dicarboxylate anions bridge tetraaquacalcium(II) units to form polymeric chains propagating along the b -axis direction. In the crystal, O—H...O and C—H...O hydrogen bonds, and offset π–π stacking interactions [intercentroid distances = 3.551 (1) and 3.746 (1) Å] involving inversion-related pyridine rings link the polymeric chains and lattice water molecules to form a supramolecular three-dimensional framework.