Synthesis and characterization of the novel hydrogen-bonded framework material (C5H5NH){AlF[O3PCH2PO2(OH)]}⋠0.61H2O

The new aluminum diphosphonate, (C5H5NH){AlF[O3PCH2PO2(OH)]}⋅0.61H2O (monoclinic, C2/c, a=18.1898(11) Å, b=10.7396(7) Å, c=12.0022(7) Å, β=105.404(2)°, V=2260.4(2) Å3, Z=8), has been synthesized by solvothermal methods and its structure determined using micro-crystal X-ray diffraction data. The material consists of infinite columnar [AlF(O3PCH2PO3)]2−∞ anions with chains of cis- and trans- vertex-sharing AlO4F2 octahedra at their core. Each methylenediphosphonate group acts as a bisbidentate ligand bonding to adjacent aluminum atoms in a chain, and directly binding to one chain only. The columnar [AlF(O3PCH2PO3)]2−∞ anions are connected together through hydrogen-bonding interactions to form a hydrogen-bonded framework material containing pyridinium cations and extra-framework water molecules within its channels.