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

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) Four inorganic‐organic hybrid compounds have been hydrothermally synthesised and subsequently characterised by single‐crystal X‐ray diffraction. By comparatively studying the photoluminescence properties of these compounds, we may conclude that the photoluminescence originates fromligand‐centred π‐π* transitions.