STUDYOFTHEDYNAMICSTRUCTURESANDEQUILIBRIA

OFB-CYCLODEXTRINWITHCYANINEDYES

TANGYa-Lin1,FENGJuan1,XIANGJun-Feng2,CHENCi-Ping2,

YANWen-peng2andXUGuang-Zhi1

(1InstituteofChemistry,theChineseAcademyofSciences,MolecularScienceCenter,Beijng100080)

(2PhotographicDepartment,InstituteofPhysicalandChemicalTechnology,

TheChineseAcademyofSciences,Beijing100101)

Abstract

Theresultsof1HNMRinvestigationofB-Cyclodextrininclusioncomplexeswiththreecya-ninedyesinD2OandDMSOsolutionarereportedinthispaper,Itwasfoundthatthereisdiffer-enceinchemicalshiftofsomeprotonsbothofB-Cyclodextrincavityandofcyaninedyesbetweenafterandbeforecomplexing,thepositionofwhichisdependentupontheinclusivedegree.Fluo-rescencespectroscopyofcyaninedyesshowedthatthefluorescenceintensityofthesedyesisobv-iouslyquenchedduetotheformingofinclusionswithB-Cyclodextrin,rmationabouthydrogenbondwasinducedfromthestudyoftemperaturede-pendenceofchemicalshiftofhydroxylprotonsinB-Cyclodextrincavity,OH-3andOH-6.TheirequilibriumconstantsofinclusioncomplexeswereobtainedfromNMRchemicalshifttitration.ThestructuremodelofthreeinclusioncomplexesanddynamicprocessenteringB-Cyclodextrincavityhasbeendescribedinthispaper.

Keywords:B-Cyclodextrin;Inclusioncomplex;Cyaninedye;Structuralmodel