The Structure of the Cyclodextrin Complex. V. Crystal Structures of α-Cyclodextrin Complexes with p-Nitrophenol and p-Hydroxybenzoic Acid
- 1 June 1977
- journal article
- research article
- Published by Oxford University Press (OUP) in Bulletin of the Chemical Society of Japan
- Vol. 50 (6) , 1416-1424
- https://doi.org/10.1246/bcsj.50.1416
Abstract
α-Cyclodextrin (α-CDx) forms a 1 : 1 complex with p-nitrophenol (p-NP) and p-hydroxybenzoic acid (p-HB). The crystal structures were determined by the X-ray method. The crystals of both complexes are orthorhombic, and the space group is P212121 with Z=4. The cell dimensions are a=13.455(1), b=15.296(1), and c=24.740(3) Å for the p-NP complex, and a=13.356(1), b=15.342(1), and c=24.896(2) Å for the p-HB complex. The crystal structures were determined on the basis of the isomorphous structure of the p-iodophenol complex by using 4811 reflections for the p-NP complex and 4692 reflections for the p-HB complex, and refined by the block-diagonal least-squares method to the final R-values of 0.066 and 0.067 respectively. In both complexes, the guest molecule is included in the α-CDx cavity, and the α-CDx ring is deformed from the regular hexagonal symmetry as a result of the inclusion of the planar molecule. The nitrophenyl or carboxyphenyl group is located in the cavity, while the phenolic hydroxyl group protrudes from the secondary hydroxyl side of the cavity. Several intermolecular hydrogen-hydrogen contacts shorter than the ideal van der Waals contact are observed between α-CDx and guest molecules, indicating that the guest molecule is rigidly fixed in the cavity. The nitro or carboxyl group is situated on the O(6) side and is hydrogen-bonded to water or a hydroxyl group of the adjacent α-CDx molecule. The geometry of the complex gives a reasonable model for the α-CDx-substrate complex in the hydrolysis of p-nitrophenyl acetate and p-carboxyphenyl acetate catalyzed by α-CDx.Keywords
This publication has 23 references indexed in Scilit:
- The Structure of the Cyclodextrin Complex. III. The Crystal Structure of the α-Cyclodextrin-Sodium Benzenesulfonate ComplexBulletin of the Chemical Society of Japan, 1976
- The Structure of the Cyclodextrin Complex. II. The Crystal Structure of α-Cyclodextrin-Methyl Orange (2 : 1) ComplexBulletin of the Chemical Society of Japan, 1976
- Topography of cyclodextrin inclusion complexes. 8. Crystal and molecular structure of the .alpha.-cyclodextrin-methanol-pentahydrate complex. Disorder in a hydrophobic cageJournal of the American Chemical Society, 1976
- X-ray studies of linear polyiodide chains in α-cyclodextrin channels and a model for the starch-iodine complexNature, 1976
- Topographie der Cyclodextrin‐Einschlußverbindungen, VII. Röntgenstrukturanalyse des α‐Cyclodextrin. Krypton‐Pentahydrats. Zum Einschlußmechanismus des Modell‐EnzymsEuropean Journal of Inorganic Chemistry, 1976
- Topography of cyclodextrin inclusion complexes. IV. Crystal and molecular structure of the cyclohexaamylose–1-propanol–4.8 hydrate complexActa Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 1974
- Topography of cyclodextrin inclusion complexes. III. Crystal and molecular structure of cyclohexaamylose hexahydrate, the water dimer inclusion complexJournal of the American Chemical Society, 1974
- Topography of cyclodextrin inclusion complexes : Part II. The iodine-cyclohexa-amylose tetrahydrate complex; its molecular geometry and cage-type crystal structureCarbohydrate Research, 1973
- Acceleration of phenyl ester cleavage by cycloamyloses. A model for enzymic specificityJournal of the American Chemical Society, 1967
- The Crystal and Molecular Structure of the Cyclohexaamylose-Potassium Acetate Complex1Journal of the American Chemical Society, 1965