α-andβ-cyclodextrinsconsistingofsixandsevenglucoseresiduesrespectively,havelipophiliccavitieswithdifferentinnerdiameters.Theyformhost-guestinclusioncomplexeswithhydrophobicorganicandorganometallicguestmoleculesinaqueoussolution.Thesehost-guestcomplexeshaveprovedtobeexcellentmodelsystemsforstudyingthenatureofnoncovalentbondingforcesinaqueousmedia.TheyhaveprovidedvaluableinsightsintothehydrophobiceffectandLondondispersionforcesandaregoodmodelforunderstandingthespecificityofenzymesubstrateinteractions[1]Evidencefortheformationofinclusioncomplexeshavebeenprovidedfromcalovimetrictitration[2]NMR[33],circulardichroism[4],UV[1]andfluorescencespectra[5]andconductometricmethod[6]etc.Herewereportanewfluorimetricmethodforastudyonthereactionofthehost-guestinclusioncomplexesofcyclodextrinwithphenols.Dissociationconstants(Kd)oftheinclusioncomplexesofsomephenolswithα-β-cyclodextrinareestimatedbasedonthevariationofthefluorescentintensityandmodifiedHarad'equations.
