A novel tetranuclear iron complex [Fe4O2(O2CC2H5)7(bipy)2]PF6•2H2O (bipy=2,2′-bipyridine):: Synthesis, crystal structure and magnetic properties

A novel tetranuclear iron-ore complex has been synthesized and characterized by X-ray single crystal structural analysis: [Fe4O2(O2CC2H5)(7)(bipy)(2)]PF6. 2H(2)O (bipy = 2,2'-bipyridine). The title complex crystallizes in the monoclinic system, space group C2/c, with lattice parameters a = 27.859(2) Angstrom, b = 13.0629(10) Angstrom, c = 17.2698(14) Angstrom, beta = 123.6080(10)degrees, V = 5234.3 (7) Angstrom (3), Dc = 1.559 Mg/m(3), Z = 4, R-1 = 0.0493. The molecular structure shows that there are two types of coordination environment for Fe(III) atoms. One is formed by two N atoms and four O atoms, another by six O atoms, all in distorted octahedron, which forms a "butterfly" core structure. The corresponding variable temperature susceptibility measurement shows the antiferromagnetic interactions in the complex.