catena-Poly[[[tetrakis(1-methylimidazole-kappaN3)copper(II)]-mu2-sulfato-kappa2O:O'] acetonitrile hemisolvate sesquihydrate].

The title compound, [Cu(C(4)H(8)N(2))(4)]SO(4).0.5CH(3)CN.1.5H(2)O, consists of a double chain wherein the Cu centres are octahedrally coordinated by four 1-methylimidazole ligands in the equatorial plane and by two axial sulfate ions which act as bridges between the Cu centres. The Cu-N bond lengths lie between 1.9929(14) and 2.0226(14)A, but the Cu-O bond distances are longer, with values between 2.3496(13) and 2.8276(14)A. The water molecules participate in the formation of a network of hydrogen bonds of significance in maintaining the connectivity of the structure.