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

A novel tetrauclear iron–oxo complex has been synthesized and characterized by X-ray single crystal structural analysis: [Fe4O2O2CC2H5)7(bipy)2]PF6·2H2O (bipy=2,2′-bipyridine). The title complex crystallizes in the monoclinic system, space group C2/c, with lattice parameters a=27.859(2) Å, b=13.0629(10) Å, c=17.2698(14) Å , β=123.6080(10)°, V=5234.3(7) Å3, Dc=1.559 Mg/m3, Z=4, R1=0.0493. The molecular structure shows that there are two types of coordination environments 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 that there exists an antiferromagnetic interaction in the complex.