Crystal structures of cyclomaltohexaose (alpha-cyclodextrin) complexes with p-bromophenol and m-bromophenol

Crystal structures of cyclomaltohexose (alpha-cyclodextrin) complexes with p-bromophenol and m-bromophenol have been determined by single-crystal X-ray diffraction. The space group of the alpha-cyclodextrin-p-bromophenol complex is P2(1)2(1)2(1) with unit cell dimensions of a = 15.318(3), b = 24.733(3), c = 13.457(2) A, and that of the alpha-cyclodextrin-m-bromophenol complex is P2(1)2(1)2 with unit cell dimensions of a = 25.858(7), b = 27.263(8), c = 8.145(3) A. In crystals, the alpha-cyclodextrin-p-bromophenol complex and the alpha-cyclodextrin-m-bromophenol complex form a layer-type and a channel-type molecular packing structure, respectively. The intermolecular hydrogen-bond interactions of the hydroxyl groups of bromophenols are closely related to the molecular packing structure.