Polynuclear clusters represent attractive candidates as supermolecular building blocks [1] for the construction of polymeric materials [2] because may combine the enhanced variety of coordination algorithms compared with single metal ions, invariant skeleton, porosity with their inherent physical characteristics, for example interesting magnetic properties, which may expands the range of potential practical applications. A new 1D coordination polymer {[Co4( 3-OMe)4(piv)4(H2O)2(pyz)] • (MeOH) • 3(H2O)}n, where Hpiv = pivalic acid and pyz = pyrazine, consisting of tetranuclear heterocubanes [3] bridged by pyrazine spacer ligands, has been synthesized. Compound crystallizes in the monoclinic space group C2/c, a=26.65(2), b=9.865(6), c=19.443(7) Å, β=93.56(4) . The heterocubane tetranuclear cluster resides around two-fold axis thus having C2 molecular symmetry (Fig. 1), while pyrazine ligand is located around inversion center. Four vertexes of distorted cube occupy tetrahedrally located Co atoms, while in another four vertexes reside methoxide ligands. There are two distinct cobalt sites, Co1 and Co2. Two pivalates chelate to each of Co2 atoms. Two further pivalates act as bridges between Co1 and Co2 atoms. The remaining coordination sites on Co1 atom are occupied by H2O molecule (O1W) and pyz ligand. In the crystal, parallel polymeric chains run along the c crystallographic axis. The solvent water molecules (O2W) hydrogen bonded with two coordinated O1W molecules and two oxygen atoms of chelating pivalates of neighbouring chain and link chains in the layer parallel to the (bc) plane. These layers are stacked by their hydrophobic surfaces in ABAB fashion. Two additional water and methanol solvent molecules are associated with each cluster moiety.