The crystal structure of the 1 : 1 complex of beta-cyclodextrin with trans-cinnamic acid

The crystal structure of the 1:1 complex of beta-cyclodextrin (cyclomaltohe ptaose) with trans-cinnamic acid was studied by X-ray diffraction. Two beta -cyclodextrin molecules related by a twofold crystal axis form dimers in th e hydrophobic cavity of which, two guest molecules are entirely buried. The complex crystallizes in the monoclinic C2 space group with channel-type mo lecular packing. The oxygen atoms of the carboxylate group of the trans-cin namic acid molecule form strong hydrogen bonds with two water molecules lyi ng in the interdimeric space of the hydrophobic channel. (C) 2000 Elsevier Science Ltd. All rights reserved.