Crystal and molecular structure of β-cyclodextrin inclusion complex with succinic acid
- 481 Downloads
The crystal complex of β-cyclodextrin with succinic acid, intermediate product of hydrolysis reaction of succinic anhydride in the presence of β-cyclodextrin, was isolated and studied by X-ray analysis (monoclinic, space group P21, a = 15.1977(7) Å, b = 10.1763(5) Å, c = 20.6943(6) Å, β = 109.239(4)°, V = 3021.8(2) Å3, Z = 2, R 1 = 0.0359, wR 2 = 0.0947). It was proved that β-cyclodextrin and succinic acid form an inclusion complex, which exists in crystal state as a heptahydrate. The molecule of succinic acid is fully included in the β-cyclodextrin cavity with its carboxyl groups accessible for water molecules. Water molecules located at borders of cavity rims and in interstices between molecules of β-cyclodextrin participate in formation of intermolecular hydrogen bonds. The overall structure does not contain disordered fragments. The crystal conformation of succinic acid corresponds to one of possible conformers of the molecule in vacuo and is almost not disturbed by intermolecular interactions in crystal. Based on the analysis of structural features of the crystal conformation of succinic acid and character of its location in the β-cyclodextrin cavity, it was suggested that hydrolysis of succinic anhydride via ring opening and formation of succinic acid is mediated by cyclodextrin microenvironment and it likely occurs near the narrow rim of the macrocycle cavity.
Keywordsβ-Cyclodextrin inclusion complex Conformational analysis Crystal structure Hydrogen bonding Mediator of reaction Succinic acid Succinic anhydride X-ray analysis
This work was supported by National Academy of Sciences of Ukraine. VB acknowledges the ICDD for financial support (Grant (03-02).
- 10.Swart, P.J., Beljaars, E., Smit, C., Pasma, A., Schuitemaker, H., Meijer, D.K.: Comparative pharmacokinetic, immunologic and hematologic studies on the anti-HIV-1/2 compounds aconitylated and succinylated HAS. J. Drug Target. 4, 109–116 (1996)Google Scholar
- 12.Neiland, O.: Organic chemistry, p. 571. Moscow, High School (1990)Google Scholar
- 13.Dawson, R.M.C., Elliot, D.C., Elliot, W.H., Jones, K.M.: Data for Biochemical Research, p. 333. Clarenton Press, Oxford (1986)Google Scholar
- 15.Sheldrick, G.M.: SHELXL-97, Release 97–2, University of Göttingen, Germany (1997)Google Scholar
- 16.HyperChem® Release 7.0 for Windows, Molecular Modeling System, Hypercube, Inc. (2002)Google Scholar
- 18.Leach, A.R.: Molecular Modelling/Principles and Applications, p. 422. Addison Wesley Longman Ltd, Essex (1996)Google Scholar
- 21.Chem 3D® Ultra Version 8.0, Molecular Modeling and Analysis, Cambridge Soft Corporation (2003)Google Scholar
- 25.Harata, K., Uekama, K., Otagiri, M., Hirayama, F.: Crystal structure of the α-CD-3-iodopropionic acid (1:1) complex pentahydrate. Nihon Kagaku Kaishi. 173–180 (1983)Google Scholar
- 29.Jefffrey, G.A.: An Inroduction to Hydrogen Bonding, p. 12. Oxford University Press, New York (1997)Google Scholar