Abstract
In the centrosymmetric title compound, [Co(C4H11N2)2(H2O)4](SO4)2·2H2O, the Co(II) atom is coordinated in a distorted octa-hedral geometry by four water O atoms and two piperazinium N atoms. These four water O atoms define an equatorial plane with a maximum deviation of 0.0384 (1) Å while the two piperazinium N atoms complete the octa-hedron in the axial positions. Neighboring complex mol-ecules and sulfate anions are connected through an extensive network of N-H⋯O and O-H⋯O hydrogen bonds, which link the different chemical species into layers in the ab plane. Additional Owater-H⋯O hydrogen bonds involving the non-coordinating water mol-ecules and C-H⋯O inter-actions connect these layers into a three-dimensional supra-molecular structure.