HYDROTHERMAL SYNTHESIS, STRUCTURE DETERMINATION, AND MAGNETIC-PROPERTIES OF A NEW LAYERED OXYFLUORINATED IRON PHOSPHATE TEMPLATED BY 1,4-DIAMINOBUTANE

F-III(PO4)(6)(H2O)(3)](H2O)(2).(H3N(CH2)(4)NH3)(3) (labeled MIL-4) was synthesized hydrothermally from a mixture of Fe2O3:P2O5:HF: 1,4-diami nobutane:H2O in the molar ratio 1:1:2:1.5: 80. Its structure was solve d by single-crystal X-ray diffraction in the noncentrosymmetric orthor hombic space group P2(1)2(1)2(1) (No. 19) with lattice parameters a = 9.5852(1) Angstrom, b = 15.5879(3) Angstrom, c = 29.2556(2) Angstrom, V = 4371.2(1) Angstrom(3), Z = 4. MIL-4 is a layered compound whose in organic layers are characterized by the presence of helicoidal chains of (FeX6)-X-III (X = O, H2O, F) corner-shared octahedra. The organic c ations located between the layers ensure both the electroneutrality of the compound and the stability of the framework by strong hydrogen bo nds. The magnetic measurements show that MIL-4 exhibits a ferrimagneti c behavior under T-C = 7(1) K.