Tetra-mu-aqua-octaaquabis(mu-4-chloropyridine2,6-dicarboxylato)bis(4-chloropyridine2,6-dicarboxylato)tricobalt(III)disodium(I) bis[triaquabis(4-chloropyridine2,6-dicarboxylato)cobalt(II)] hexahydrate

The title compound, [Co3Na2(C7H2ClNO4)(4)(H2O)(12)][Co(C7H2ClNO4)(H2O)(3)](2)center dot 6H(2)O, consists of a centrosymmetric dimer of [Co-II(dipicCl)(2)](2-) complex dianions [dipicCl is 4-chloropyridine- 2,6-dicarboxylate] bridged by an [Na2CoII(H2O)(12)](4+) tetracationic cluster, two independent [Co(dipicCl)(H2O)(3)] complexes, and six water molecules of crystallization. The metals are all six-coordinate with distorted octahedral geometries. The [Co-II(dipicCl)(H2O)(3)] complexes are neutral, with one tridentate ligand and three water molecules. The [Co-II(dipicCl)(2)](2-) complexes each have two tridentate ligands. The [Na2CoII(H2O)(12)](4+) cluster has a central Co-II ion which is coordinated to six water molecules and lies on a crystallographic inversion center. Four of the water molecules bridge to two sodium ions, each of which have three other water molecules coordinated along with an O atom from the [Co-II(dipicCl)(2)](2-) complex. In the crystal structure, the various units are linked by O-H center dot center dot center dot O hydrogen bonds, forming a three-dimensional network. Two water molecules are disordered equally over two positions.