A cobalt coordination polymer, {[Co(L1)2(H2O)2] · (HCOO)2 · H2O}n, where L1 is a bis(4-(1H-imidazol-1-yl)phenyl)methanone, has been synthesized and characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The crystal crystallizes in the triclinic sp. gr. with the unit cell parameters a = 7.9504(6), b = 10.0231(7), c = 13.3129(8) Å, and α = 88.399(5)°, β = 75.310(6)°, γ = 79.179(6)°, Z = 1. The Co2+ ion has a distorted octahedral environment with two O atoms from two water molecules and four N atoms from four L1 ligands. A thermal stability of polymer has been discussed. [ABSTRACT FROM AUTHOR]