SYNTHESIS, THERMAL-BEHAVIOR, AND STRUCTURE OF O(HYDROGENETHYLENEDIAMINETETRAACETATO)FERRATE(III) - A MOLECULAR PRECURSOR FOR STOICHIOMETRICNICKEL FERRITE

Hexaaquanickel(II) (hydrogenethylenediaminetetraacetato)ferrate(III), [Ni(H2O)(6)]-[FeCl(EDTA)H](2) . 4H(2)O, was prepared by the reaction o f nickel(II) chloride with (hydrogenethylenediammine)iron(III) in wate r at room temperature. The compound readily loses water at room temper ature depending on drying conditions and the relative humidity. The mo lecular structure of the dihydrate was determined by single-crystal X- ray crystallography. The compound decomposes in stages involving, succ essively, loss of water, pyrolysis of the EDTA ligand, and loss of HCl to yield, finally, stoichiometric nickel ferrite. Crystal data: C20H4 2N4O24Cl2Fe2Ni M = 963.88, monoclinic, space group P2(1)/c, a = 20.548 (3) Angstrom, b = 7.401(1) Angstrom, c = 12.827(1) Angstrom, beta = 10 1.78(1)degrees, V = 1909.6(7) Angstrom(3), Z = 2, D-calc = 1.68 g cm(- 3), R = 0.028, and R(w) = 0.040.