Syntheses and structures of the MOF-type series of metal 1,4,5,8,-naphthalenetetracarboxylates M_2(OH)_2[C_(14)O_8H_4] (Al, Ga, In) with infinite trans-connected M-OH-M chains (MIL-122)

摘要

Three new isostructural MOF-type compounds (named MIL-122) have been obtained from the hydro-thermal reaction at 210 deg C for 24 h of the 1,4,5,8-naphthaIenetetracarboxylic acid with aluminum, gallium or indium source in water. The structures of the compounds M_2(OH)_2[C_(14)O_8H_4] (M = Al, Ga, In) have been solved ab initio from powder X-ray diffraction analysis using the synchrotron radiation (Soleil; station CRISTAL). The three-dimensional organic-inorganic framework exhibits infinite straight chains of metal-centered octahedra sharing trans corners linked to each other through the 1,4,5,8-naphthalenete-tracarboxylate ligand. The cations Al, Ga or In, are coordinated by four oxygen atoms coming from the carboxyl groups and two bridging hydroxyl groups mu 2-OH, located in trans position in the octahedral surrounding. The compounds characterized by thermogravimetric and thermodiffraction analyses are thermally stable up to 440,460 and 380 deg C, for Al, Ga and In, respectively. Crystal data: monodinic cell; P2_1/c (n deg 14); for MIL-122 (Al): a = 9.5174(2), b = 10.0706(1), c= 6.6465(2) A, beta = 91.2614(5) deg, V = 636.878(2) A~3, Z=2; for MIL-122 (Ga): a = 9.6501(1), b = 10.0585(1), c = 6.75069(9) A, beta = 92.4786(9) deg, V= 654.65(1) A~3, Z=2; for MIL-122 (In): a = 9.92359(5), b = 10.19765(7), c= 7.19357(4) A, beta = 727.034(8) deg, V= 727.034(8) A~3, Z=2.