CRYSTAL, MOLECULAR, AND ELECTRONIC-STRUCTURE OF CARBOXYLATE [FE3O(CH3COO)6(H2O)3]NO3.4H2O

Results of X-ray structural analysis, IR spectroscopy, and quantum che mical study of the [Fe3O(CH3COO)6(H2O)3]NO3.4H2O complex are reported. The crystal belongs to the monoclinic system with a = 15.688(3), b = 11.767(2), c = 15.318(4) angstrom, gamma = 92.54(3)-degrees, space gro up P2(1)/a, R = 0.078. The molecule has a trinuclear structure: three iron atoms occupy the vertices of an equilateral triangle with an Fe-F e distance of 3.29 angstrom and are bonded by the mu3-oxo and mu-CH3CO O- (O, O') ligands. To each iron atom, one water molecule is coordinat ed. Using the obtained values of populations on 3d AO of Fe (d(xy)1.34 ; d(xz)1.39; d(yz)1.46; d(z2)1.31; d(x2-y2)1.40) and charges on oxygen atoms (O(c)-0.35; O(ac)-0.31; O(w)-0.31), we estimated the values of isomeric shift and quadrupole splitting (0.75 and 0.70 mm/sec, respect ively; these are close to the experimental values of 0.75 and 0.58 mm/ sec (300 K)).