Crystal structure of catena-poly[bis(formato-κO)bis-[µ2-1,1'-(1,4-phenyl-ene)bis-(1H-imidazole)-κ(2) N (3):N (3')]cobalt(II)].

ABSTRACT

A red block-shaped crystal of the title compound, [Co(HCOO)2(C12H10N4)2] n , was obtained by the reaction of cobalt(II) nitrate hexa-hydrate, formic acid and 1,1'-(1,4-phenyl-ene)bis-(1H-imidazole) (bib) mol-ecules. The asymmetric unit consists of one Co(II) cation, one formate ligand and two halves of a bib ligand. The central Co(II) cation, located on an inversion centre, is coordinated by two carboxyl-ate O atoms and four N atoms from bib ligands, completing an octa-hedral coordination geometry. The Co(II) centres are bridged by bib ligands, giving a two-dimensional net. Topologically, taking the Co(II) atoms as nodes and the bib ligands as linkers, the two-dimensional structure can be simplified as a typical sql/Shubnikov tetra-gonal plane network. The structure features C-H⋯O hydrogen-bonding inter-actions between formate and bib ligands, resulting in a three-dimensional supra-molecular network.