Crystal structure and magnetic properties of an octacyanometalate-based three-dimensional tungstate(V)-manganese(II) bimetallic assembly.

A single crystal of the title compound [MnII6(H2O)9[W(V)(CN)8]4 x 13H2O]n was synthesized in a hot aqueous solution containing octacyanotungstate, Na3[W(CN)8] x 3H2O, and Mn(ClO4)2 x 6H2O. The compound crystallized in the monoclinic system, space group P2(1)/c with cell constants a = 15.438(2) A, b = 14.691(2) A, c = 33.046(2) A, beta = 94.832(9) degrees, and Z = 4. The crystal consists of a W(V)-CN-MnII linked three-dimensional network [[MnII(H2O)]3[MnII(H2O)2]3[W(V)(CN)8]4]n and H2O molecules as crystal solvates. There are two kinds of W sites: one is close to a dodecahedron geometry with six bridging and two terminal CN ligands; the other is close to a bicapped trigonal prism with seven bridging and one terminal CN ligands. The field-cooled magnetization measurement showed that the compound exhibits a spontaneous magnetization below Tc = 54 K. Further magnetization measurements on the field dependence reveal it to be a ferrimagnet where all of the MnII ions are antiparallel to all the W(V) ions.