Hydrothermal Synthesis, Structural Characterisations, and Photoluminescence Properties of Four Inorganic‐Organic Hybrid Compounds in the Indium/Gallium Iodate Family

Abstract

Four inorganic-organic hybrid compounds with the formulae In2(IO3)6(H2O)(2,2′-bipy)·H2O (1), In2(IO3)6(H2O)(1,10-phen)·H2O (2), Ga(IO3)3(2,2′-bipy)·HIO3 (3) and Ga(IO3)3(1,10-phen)·H2O (4) were hydrothermally synthesised at 100 °C over 7 d and subsequently characterised by single-crystal X-ray diffraction. The bidentate diamine ligands 2,2′-bipy and 1,10-phen in the In/I/O system give rise to the compounds In2(IO3)6(H2O)(2,2′-bipy)·H2O and In2(IO3)6(H2O)(1,10-phen)·H2O which crystallise in the monoclinic space group P21/c. Using the same bidentate diamine ligands, namely 2,2′-bipy and 1,10-phen, in the Ga/I/O system led to the formationof Ga(IO3)3(2,2′-bipy)·HIO3 and Ga(IO3)3(1,10-phen)·H2O which crystallise in the monoclinic space group P21/n. Both, In2(IO3)6(H2O)(2,2′-bipy)·H2O and In2(IO3)6(H2O)(1,10-phen)·H2O possess 2D layered structures, with the former consisting of [In(H2O)(IO3)5]2– clusters and [In(IO3)(2,2′-bipy)]2+ chains and the latter consisting of [In(H2O)(IO3)5]2– clusters and [In(IO3)(1,10-phen)]2+ chains. Compound Ga(IO3)3(2,2′-bipy)·HIO3 is a 1D ribbon built up from [IO3] pyramids, [GaO4N2] octahedra and distinct [I2O6] units and featuring interesting left and right helical chains. Compound Ga(IO3)3(1,10-phen)·H2O has a 1D chain-like structure constructed from the alternation of [GaO4N2] octahedra and [IO3] pyramids. By comparatively studying the photoluminescence properties of these compounds, we may conclude that the photoluminescence originates from ligand-centred π-π* transitions. The synthesised products were further characterised by powder X-ray diffraction, thermogravimetric analysis, IR spectroscopy, ICP and elemental analysis.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)