Hybrid open-frameworks: hydrothermal synthesis, structure determinations and magnetic properties of MIL-29, two copper diphosphonates (Cu-II(H2O))(2){O3P-X-PO3} with X=C2H4, CH2-C6H4-CH2

Two copper diphosphonates were hydrothermally synthesized using ethylenedip hosphonic and p-xylenediphosphonic acids, synthesized according the Arbuzov method. The structure of (Cu-II(H2O))(2)(O3P-CH2-CH2-PO3} already describe d fr om powder data, was solved from single crystal data. Its symmetry is m onoclinic (space group P2(1)/c (no. 14)) with lattice parameters a =8.0670( 4) Angstrom: b=7.5889(4) Angstrom, c=7.3997(4) Angstrom, beta=116.281(2)deg rees, V=406.18(4) Angstrom, Z=2, The structure of (Cu-II(H2O))(2)(O3P-CH2-( C6H4)-CH2-PO3} was solved by powder X-ray diffraction (space group P2(1)/c (no. 14)) with lattice parameters a=10.812(1) Angstrom, b=7.577(1) Angstrom , c=7.412(1) Angstrom, beta=92.34(1)degrees, V-606.7(2) Angstrom(3), Z=2. B oth structures are built up from identical inorganic layers covalently link ed by the organic chains which act as pillars. The inorganic layers contain dimers of edge-sharing CuO4(H2O) square pyramids linked by the PO3C tetrah edral Both compounds are antiferromagnetic at 4(1) K. (C) 2000 Elsevier Sci ence Ltd. All rights reserved.