Synthesis and characterization of a one-dimensional inorganic–organic hybrid iron phosphate: [Fe(bipy)(HPO4)(H2PO4)] (bipy=2,2′-bipyridyl) with anti-ferromagnetic property

A coordinated iron phosphate, Fe(bipy)(HPO4)(H2PO4) (I), has been hydrothermally synthesized and characterized by elemental analysis, thermogravimetric analysis, and single crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group P21/n (No. 14), with cell parameters M=405.00, a=10.904(4) Å, b=6.4210(2) Å, c=19.294(9) Å, β=101.24(4) Å3, V=1324.9(9) Å3, Z=4, R1 [I>2((I))=0.0357, wR2 [I>2((I))=0.0717. This compound displays a new structure of ladder-like chains, in which each one-dimensional chain is constituted by the distorted octahedral units of Fe3+ bridged through PO4 tetrahedra. The bipy ligands in the compound bind in a bidentate fashion to the iron atoms and the ladder-like structure of the compound extends into a three-dimensional supramolecular array via π–π stacking interactions of bipy ligands and strong hydrogen bonding between the chains. Mössbauer spectroscopy shows the presence of Fe3+ in the octahedral coordination. Magnetic susceptibility measurements show that this material may model as anti-ferromagnetic.