Inorganic-organic hybrid materials: synthesis and crystal structure determination from powder diffraction data of Pb2(O3PCH2C6H4CH2PO3)

A new lead diphosphonate, Pb₂(O₃PCH₂C₆H₄CH₂PO₃) was hydrothermally synthesized from tetraethyl α,α′-p-xylenediphos-phonate and Pb(NO₃)₂. The structure was solved and refined using X-ray powder diffraction data. It crystallizes in the monoclinic space group P2₁/c, with a = 467.84(2), b = 2007.98(9), c = 639.10(2) pm, β = 101.020(3)°, V = 589.31(4) 10⁶ pm, Z=2, wR_p=0.034, R_p=0.027, R_F2=0.061, R_F=0.036. The structure is built from corner-linked [PbO₄] polyhedra, containing a lone pair of electrons. These polyhedra are connected to layers by phosphonate groups, RPO₃²⁻ and through the organic diphosphonic acid to a three-dimensional structure. Thermogravimetric as well as IR spectroscopic studies are also presented.