Isolation and structural characterization of new indium(III) aqua complexes: trans-[InCl2(H2O)(4)](+) and trans-[InCl4(H2O)(2)](-) as supramolecular adducts with cucurbituril and related studies

Aqua and aqua-chloride complexes of Al-III and In-III have been isolated fr om aqueous solutions and structurally characterized by X-ray analysis as su pramolccular adducts with cucurbituril. Using this approach, trans-[InCl2(H 2O)(4)](+) and trans-[InCl4(H2O)(2)](-) species were detected and isolated for the first time as parts of supramolccular assemblies of [InCl2(H2O)(4)] (3)Cl-3.(C36H36N24O12).4H(2)O (1) and (H3O)(3)-[InCl4(H2O)(2)](3) .2(C36H36 N24O12).17H(2)O (2). The hexaaqua indium(III) cation is present in [In(H2O) (6)](NO3)(3).- (C36H36N24O12).9H(2)O (3), and its geometry has been establi shed by X-ray crystallography for the first time. The preparation and cryst al structure of an Al-III hexaaqua ion - cucurbituril adduct [Al(H2O)(6)]Cl -3.(C36H36N24O12).18H(2)O (4) is also reported. A comparison of In-III with its analogs in Group 13 shows closer similarity between In-III and Tl-III in the chloroaqua complexes than between In and its lighter congeners.