Metal-Complex Ferrimagnets with the Formula {NBu4[M(II)Fe(III)(ox)3]}3∞ (NBu4+ = Tetra(n-butyl)ammonium Ion, ox2− = Oxalate Ion, M = Fe2+, Ni2+)

Mixed-metal assemblies {NBu4[M(II)Fe(III)(ox)3]}3∞ (M = Ni (1), Fe (2), Mn, Zn) have been prepared and characterized, where NBu4+ = tetra(n-butyl)ammonium ion, ox2− = oxalate ion. Each assumes a three-dimensional network structure consisting of alternately arrayed Fe(III) and M(II) ions. The compounds 1 and 2 are shown to be ferrimagnet with a magnetic phase-transition temperature of 28 and 43 K, respectively.