Spectrometric and 2D NMR Studies on the Complexation of Chlorophenols with Cyclodextrins |
| |
Authors: | Elisa Leyva Edgar Moctezuma Jane Strouse Miguel A. García-Garibay |
| |
Affiliation: | (1) Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, S.L.P, 78210, Mexico;(2) Department of Chemistry and Biochemistry, University of California, Los Angeles, 90024-1569, U.S.A |
| |
Abstract: | The formation and structure of inclusion complexes of - and-cyclodextrins with 2-chlorophenol (2CP), 3-chlorophenol (3CP),4-chlorophenol (4CP), 2,4-dichlorophenol (24DCP), 2,6-dichlorophenol(26DCP) and 3,4-dichlorophenol (34DCP) have been studied by UV-VIS and1H NMR spectroscopy. Both cyclodextrins were found to form 1:1inclusion complexes. Bindingconstants estimated from titration studies revealed that the stability of the complexes was highly dependent on the structure and polarity of the chlorophenol and on the cyclodextrin used. In general, weaker binding constants were observed for a given chlorophenol with -cyclodextrin than with-cyclodextrin. The weakest binding constants (Kb < 200 M-1) were obtained for the ortho-substituted chlorophenols (2CP and 26DCP) and the largest binding constants were obtained between para-chlorophenols (4CP, 24DCP and 34DCP) and-cyclodextrin. 2D-TROESY studies of chlorophenol-cyclodextrincomplexes in D2O provided insight into the structure of the complexes. |
| |
Keywords: | /content/k4862664454428ut/xxlarge945.gif" alt=" agr" align=" BASELINE" BORDER=" 0" >- and /content/k4862664454428ut/xxlarge946.gif" alt=" beta" align=" MIDDLE" BORDER=" 0" >-cyclodextrin chlorophenol complexes 2D 1H NMR TROESY inclusion complex structures spectrophotometry 1H NMR equilibrium constants |
本文献已被 SpringerLink 等数据库收录! |
|