title: [Study on the inclusion behavior of cucurbit [7] uril with methylene blue by spectrofluorometric titrations].
abstract: The characteristics of host-guest complexation between cucurbit [7] uril (CB7) and methylene blue (MB) were investigated by fluorescence spectrometry in acetate buffer solution at room temperature. It was found that the fluorescence intensity of methylene blue regularly increased upon the addition of cucurbit [7] uril accompanying with a blue-shift of the position of the emission maximum. The results indicate the formation of complex between CB7 and MB at a 1 : 1 complex stoichiometry and the association constant was calculated by applying a deduced equation. 1H NMR spectra were applied to to complement the fluorescence work to verify the formation of the complex. From the temperature dependence of the equilibrium constants, thermodynamics parametersH andS values were obtained, indicating an enthalpic driving force for complexation. The possible interaction mechanism was also discussed. This work may extend the application range of cucurbit [7] uril in biochemistry and pharmaceutical analysis.
authors.affiliation: Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China. yhp123@mail.ahnu.edu.cn
authors.forename: Hua-peng
authors.initials: HP
authors.lastname: Yu
authors.forename: Jun-yong
authors.initials: JY
authors.lastname: Sun
authors.forename: Lian
authors.initials: L
authors.lastname: Wu
authors.forename: Hong-wei
authors.initials: HW
authors.lastname: Xu
authors.forename: Lun
authors.initials: L
authors.lastname: Wang
authors.forename: Yun-you
authors.initials: YY
authors.lastname: Zhou
mesh_terms: D001952:Bridged-Ring Compounds / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry*; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013816:Thermodynamics; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils
chemical_list: D001952:Bridged-Ring Compounds; D005456:Fluorescent Dyes; D007093:Imidazoles; D008751:Methylene Blue; C456276:cucurbit(7)uril; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils