Octacyanotungstate(V)-based square W2M2 (M = Co, Mn) complexes: synthesis, structure and magnetic properties

The preparation, single-crystal X-ray crystallography and magnetic properties are reported for two tetranuclear cluster complexes based on [W-V(CN)(8)](3-) octacyanometallates. Reactions of [W-V(CN)(8)](3-) with Co-II ions in the presence of the capping ligand tpm (tpm = tri(1H-pyrazol-1-yl) methane) lead to the formation of complex 1 [(tpm)(2)Co-II][W-2(V)(CN)(16)Co-2(tpm)(2)(H2O)(2)]center dot 4H(2)O. Analogous reactions with the Mn-II produce complex 2 [(tpm)(2)Mn-II][W-2(V)(CN)(16)Mn-2(tpm)(2)(H2O)(2)]center dot 4H(2)O. Complexes 1 and 2 are isomorphous and crystallize in the space group of P (1) over bar. Magnetic investigation shows the ferromagnetic coupling between Co-II and W-V ion in complex 1, while the antiferromagnetic interactions between Mn-II and W-V in complex 2. Further magnetic studies indicate the presence of spin glasses in complex 2, which may be attributed to the further ferromagnetic coupling between anionic and/or cationic cores.