TETRAPOTASSIUM MU-CARBONATO-MU-OXO-BIS[NITRILOTRIACETATOIRON(III)] DIMETHANOL DIHYDRATE

The structure of a mu-carbonato-mu-oxo-diiron(III) complex with the tetradentate tripodal ligand nitrilotriacetate (nta), [Fe2(nta)2(CO3)O]4-, has been determined by single-crystal X-ray diffraction for the potassium salt, K4[Fe2(C6H6NO6)2(CO3)O].2CH3OH.2H2O. The binuclear complex has crystallographic twofold symmetry and the coordination geometry around the Fe atoms is distorted octahedral. The F-O-Fe bridge angle is 121.1(2)-degrees and the Fe...Fe interatomic distance is 3.188 (1) angstrom. The Fe2(CO3)O core is not planar; the dihedral angle between the Fe2O and CO3 planes is 33.8 (5)-degrees.