catena-Poly[[[diaquadiformatocobalt(II)]-μ-1,4-bis(1H-benzimidazol-1-yl)benzene] dihydrate]

In the title coordination polymer, {[Co(CHO2)2(C20H14N4)(H2O)2]·2H2O}n, the CoII atom (site symmetry -1) is coordinated by two formate O atoms, two water O atoms and two N atoms from two 1,4-bis(1H-benzimidazol-1-yl)benzene ligands (L), resulting in a distorted trans-CoN2O4 octahedral coordination environment. The complete L ligand is generated by crystallographic inversion symmetry and serves to bridge the cobalt ions into a chain propagating in [1-1-1]. The dihedral angle between the central benzene ring and the imidazole ring system is 38.48 (12)°. O—H...O hydrogen bonds involving both the coordinated and uncoordinated water molecules occur and help to link the chains together.