Beta-cyclodextrin Inclusion Complex Crystal Structure Study

Cyclodextrins are the products of the starch which is degraded by the glucosyltransferase enzyme. They are serious of cyclic oligosaccarides. Cyclodextrins consist of several D-glucopyranoside units which are linked by α-1 ,4-glycosidic linkages. They can act as hosts in inclusion complexes with a wide variety of small molecules, depending on the weak molecular interactions. The study of the structures of Cyclodextrins and their inclusion complexes is very essential for understanding the detailed mechanism of complex formation. Single crystal X-ray diffraction is a most powerful method of providing the three-dimensional structure of inclusion complexes. So the study of Cyclodextrins and their inclusion complexes can help us understand the weak molecular interactions deeply and reveal the nature of inclusion complexes. The main contents are shown as follows: 1. Cyclodextrin chemistry are discussed in summary. The present of β- Cyclodextrins and their inclusion complexes'crystal structure are reviewed. Then point out the aims and tasks of this dissertation. 2. Design and synthesis β-cyclodextrin-n-butylaminethe, the crystal structures of new β-cyclodextrin hydrate and β-cyclodextrin-n-butyl- aminethe are determined by X-ray diffraction method. And then discussed their structures. 3. Some quantum chemistry parameters of several β- cyclodextrin inclusion complexes are calculated. And then discussed the changes of binding energies, dipoles, atomic charges and the molecular orbitals in order to find the nature of the weak molecular interactions.