The Studies Of β-Cyclodextrin Inclusion Complexes

Cyclodextrins(CDs)possess a hydrophilic exterior,which makes them soluble in water,and an interior cavity which is less polar than water.These properties enable CDs to incorporate guest molecules on the basis of size and hydrophobicity.It is well established that CDs are size-selective complexes with aromatic hydrocarbons through host-guest interactions.If the guest molecules are metallo—organic species,the CDs host can be considered as second-sphere ligand noncovalently bonded to the first sphere ligands.These types of inclusion complexes are of fundamental significance because the weaker categories of noncovalent bonding assume considerable importance.These inclusion complex can modify the properties of the guest compared to the bulk material,e.g.,in their spectra characteristics,nonlinear optical properties and ligand substitution/insertion reactions.Almost all organic dye molecules consist of conjugated groups,which are consistent with CDs's cavities in size.The spectra characteristics of these dyes will change envidently,when forming inclusion complex with CDs.The study between organic dyes and CDs will provide methods determining the content of organic dyes.Out of the above consideration,it is very important to study the CDs inclusion complexes containing metallo-organic compound or organic dyes.Some innovative ideas performed in this paper have been shown as below:1.β-Cyclodextrin(β-CD)inclusion complexes containing two kinds of metallo-organic compounds were prepared and characterized.When forming inclusion complex,the spectra characteristics and thermal stabilities of guests were improved.2.The interaction between hematoxylin(Hemt)andβ-CD has been studied.The thermodynamic parameters(enthalpy changeΔH,entropy changeΔS and Gibbs free energy changeΔG)of the reaction associated with the inclusion mechanism were also preliminarily discussed.This dissertation consists of four chapters:Chapter 1:The principle of the forming of CDs inclusion complex was reviewed. Furthermore,the physical,chemical characteristics and the methods of preparing inclusion complex,associated with the applications,were expounded.Chapter 2:An inclusion complex consisting ofβ-CD and di(8-hydroxyquinoline) magnesium was prepared,which was characterized by NMR,TGA,IR.The Job's method and elemental analysis provided 2:1 stoichiometry for the inclusion complex between host and guest.The thermal stability and solubility of guest were improved when forming inclusion complex.Chapter 3:An inclusion complex containingβ-CD and Eu(PMBP)₃[PMBP= 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5]was obtained by microwave synthesis method.The formation of the inclusion complex was supported by NMR,XRD,TGA and IR.Enhanced hypersensitive transition at 611 nm(⁵D₀→⁷F₂)emission intensity of Eu³⁺ was observed,accompanied by the excitation peaks shifted to lower energy,compared with Eu(PMBP)₃.Chapter 4:The interaction between hematoxylin andβ-CD has been studied by fluore,scence,UV-VIS absorption spectra and circular dichroism(CD)spectra. Hematoxylin can form 1:1 inclusion complex withβ-CD concluded form Job's method. The acidity,temperature and surfactants effects on the inclusion system were also studied.