In the title cobalt(II) coordination polymer with isobutyrate ligands, {[Co{CH(CH3)2CO2}2(H2O)]·H2O} n , the Co2+ ion is hexa-coordinated in a slightly distorted octa-hedral coordination environment defined by two O atoms from two bridging water mol-ecules and four O atoms from four bridging carboxyl-ate ligands. The carboxyl-ates adopt two different coordination modes, μ-(κ2O:O') and μ-(κ2O:O), forming a one-dimensional polymeric chain extending along [010]. The intra-chain cobalt⋯cobalt separation is 3.2029 (2) Å. The polymeric chains are linked by hydrogen bonds involving the water mol-ecules of solvation, giving a two-dimensional network structure lying parallel to (100).
Keywords: cobalt carboxylates; cobalt(II) isobutyrate dihydrate; coordination polymer; crystal structure; polynuclear complexes.