Synthesis and characterization of two-dimensional fluorinated metal phosphates incorporating 2,2′-bipyridine ligands:: M2F2(2,2′-bpy) (HPO4)2(H2O) (M = Fe, Ga)

Two fluorinated metal phosphates, M2F2(2,2'-bpy)(HPO4)(2)(H2O) (M= Fe, Ga), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and magnetic susceptibility. The two compounds are isostructural and crystallize in the triclinic space group p (1) over bar, a 7.6595(8) Angstrom, b = 10. 101 (1) Angstrom, c = 11.260(1) Angstrom, alpha = 107.555(2)degrees, beta = 105.174(2)degrees, gamma = 98.975(2)degrees, V = 775.1(2) Angstrom(3) and Z = 2 for the Fe compound, and a = 7.5816(6) Angstrom, b = 9.9943(7) Angstrom, c = 11.1742(8) Angstrom, alpha = 107.333(1)degrees, beta = 105.014(1)degrees, gamma = 99.261(1)degrees and V = 754.2(2) Angstrom(3) for the Ga compound. They are the first fluorinated metal phosphates which incorporate 2,2-bipyridine ligands. The structure consists of edge-sharing octahedral dimers with the composition Fe2F4(H2O)(2)O-4 and discrete FeN2O4 octahedra, which are linked into two-dimensional sheets through corner-sharing phosphate tetrahedra. The 2,2'-bpy ligands bind in a bidentate fashion to the metal atoms and project into interlamellar region. The layers are extended into a three-dimensional supramolecular array via pi-pi stacking interactions of M the 2,2'-bpy ligands. Magnetic susceptibility of the iron compound confirms the presence of Fe-III. (C) 2003 Elsevier Science (USA). All rights reserved.