title: Spectral study on the interaction of cryptophane-A and neutral molecules CHnCl4-n (n=0, 1, 2).
abstract: Cryptophane-A was synthesized from vanillin by a three-step method and its spectroscopic properties in different organic solvents were determined. Two absorption bands at about 240-250 and 280-290 nm were observed for cryptophane-A. A fluorescence emission peak was obtained at 320-330 nm using a solution of approximately 10(-5)M cryptophane-A. The interaction of cryptophane-A with chlorinated compounds CH(n)Cl(4 - n) (n=0, 1, 2) in dioxane and ethyl acetate solvents were studied in detail by fluorescence spectroscopy, respectively. The results show that cryptophane-A is well suited for inclusion of CH(2)Cl(2) to form a stable 1:1 complex and the binding constant was estimated to be 19+/-2M(-1). These results were also confirmed by (1)H NMR and CPK models. Larger similar molecules such as CHCl(3) and CCl(4) are unable to enter the cavity of cryptophane-A because of their bigger sizes. However, the fluorescence emission of cryptophane-A can be efficiently quenched by CHCl(3) and CCl(4), following the Stern-Volmer relationship.
authors.affiliation: Center of Environmental Science and Engineering Research, Shanxi University, Taiyuan 030006, PR China.
authors.forename: Caihong
authors.initials: C
authors.lastname: Zhang
authors.forename: Weili
authors.initials: W
authors.lastname: Shen
authors.forename: Guangming
authors.initials: G
authors.lastname: Wen
authors.forename: Jianbin
authors.initials: J
authors.lastname: Chao
authors.forename: Liping
authors.initials: L
authors.lastname: Qin
authors.forename: Shaomin
authors.initials: S
authors.lastname: Shuang
authors.forename: Chuan
authors.initials: C
authors.lastname: Dong
authors.forename: Martin M F
authors.initials: MM
authors.lastname: Choi
mesh_terms: D001665:Binding Sites; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D011083:Polycyclic Compounds; D012997:Solvents; D013050:Spectrometry, Fluorescence / Q000379:methods; D014230:Triazoles / Q000737:chemistry*
chemical_list: D006843:Hydrocarbons, Chlorinated; D046911:Macromolecular Substances; D011083:Polycyclic Compounds; D012997:Solvents; D014230:Triazoles; C523242:cryptophane