Spectral study on the interaction of cryptophane-A and neutral molecules CHnCl4-n (n=0, 1, 2)

Talanta. 2008 Jul 15;76(2):235-40. doi: 10.1016/j.talanta.2007.11.047. Epub 2007 Nov 24.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Hydrocarbons, Chlorinated / chemistry*
  • Macromolecular Substances / chemistry*
  • Magnetic Resonance Spectroscopy
  • Polycyclic Compounds
  • Solvents
  • Spectrometry, Fluorescence / methods
  • Triazoles / chemistry*

Substances

  • Hydrocarbons, Chlorinated
  • Macromolecular Substances
  • Polycyclic Compounds
  • Solvents
  • Triazoles
  • cryptophane