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Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Topography of the 1:1 alpha-cyclodextrin-nitromethane inclusion complex
T Nakagawa1, S Immel, F W Lichtenthaler
1Institut für Organische Chemie, Technische Universität Darmstadt, Germany.
Carbohydrate Research
|March 7, 2000
Summary
Alpha-cyclodextrin (alpha-CD) readily forms inclusion complexes with nitromethane in aqueous solutions. This study details the crystal structure of the alpha-CD-nitromethane pentahydrate complex, revealing key interactions.
Area of Science:
- Supramolecular Chemistry
- Crystallography
- Host-Guest Chemistry
Background:
- Alpha-cyclodextrin (alpha-CD) is a cyclic oligosaccharide known for its ability to form inclusion complexes with various guest molecules.
- Understanding the precise structural details of these complexes is crucial for applications in drug delivery, separation science, and catalysis.
Purpose of the Study:
- To elucidate the crystal structure of the nitromethane inclusion complex with alpha-cyclodextrin.
- To investigate the molecular interactions stabilizing the complex and the role of the co-solvent in complex formation.
Main Methods:
- Single crystal X-ray diffraction analysis was employed to determine the crystal structure.
- The crystallization process involved dissolving alpha-cyclodextrin in a 9:1 water-nitromethane mixture.
Main Results:
- The title compound, alpha-cyclodextrin-nitromethane pentahydrate, crystallizes in the P2(1)2(1)2(1) space group.
- The alpha-CD macrocycle adopts an unstrained conformation, stabilized by inter-residue hydrogen bonds.
- Nitromethane occupies two sites within the alpha-CD cavity, interacting via van der Waals forces and C-H...O hydrogen bonds.
Conclusions:
- The study demonstrates the facile formation of nitromethane inclusion complexes with alpha-CD in aqueous media.
- The observed structure highlights the expulsion of water from the alpha-CD cavity by the more hydrophobic nitromethane guest.
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