title: Spectrofluorometric study on the inclusion behavior of p-(p-carboxyl benzeneazo) calix[4]arene with norfloxacin.
abstract: Spectrofluorometric titrations have been performed to investigate the inclusion behavior of p-(p-carboxyl benzeneazo) calix[4]arene (CBC4A) with norfloxacin (NFLX) in NaAc-HAc buffer solution (pH=5.0). It was found that the fluorescence intensity of NFLX quenched regularly upon the addition of CBC4A. The results indicated 1:1 complex stoichiometry and an association constant of 8.21 x 10(5) L mol(-1) at 20.0 degrees C were calculated by applying a deduced equation. Job's plot also verified the existence of 1:1 inclusion complex. The proposed interaction mechanism indicates that NFLX goes into (or partially goes into) the cavity of CBC4A with the help of hydrogen bonding and other forces. The various factors (pH value, ionic strength, and surfactants) affecting the inclusion process were examined in details.
authors.affiliation: Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China. zy1612992@mail.anhu.edu.cn
authors.forename: Yunyou
authors.initials: Y
authors.lastname: Zhou
authors.forename: Hongwei
authors.initials: H
authors.lastname: Xu
authors.forename: Huapeng
authors.initials: H
authors.lastname: Yu
authors.forename: Liu
authors.initials: L
authors.lastname: Chun
authors.forename: Qin
authors.initials: Q
authors.lastname: Lu
authors.forename: Lun
authors.initials: L
authors.lastname: Wang
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D047250:Calixarenes / Q000737:chemistry*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009643:Norfloxacin / Q000737:chemistry*; D009994:Osmolar Concentration; D012965:Sodium Chloride / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: C531300:4-(4-carboxylbenzeneazo)calix(4)arene; D001391:Azo Compounds; D002593:Cetrimonium Compounds; D013501:Surface-Active Agents; D047250:Calixarenes; D012965:Sodium Chloride; D009643:Norfloxacin; D000077286:Cetrimonium