Analytical Sciences


Abstract − Analytical Sciences, 17(4), 539 (2001).

Fluorescence Enhancement of Coumarin-6-sulfonyl Chloride Amino Acid Derivatives in Cyclodextrin Media
Salma M. Z. AL-KINDY,  Fakhr Eldin O. SULIMAN, and Abdalla A. AL-HAMADI
College of Science, Department of Chemistry, P. O. Box 36, Al-Khod 123, Muscat, Sultanate of Oman
Coumarin-6-sulfonyl (6-CS) amino acid derivatives form inclusion complexes with alpha- and beta-cyclodextrins (CD) in aqueous solution. The stoichiometry of the inclusion complex and the equilibrium constant were investigated. Using a fluorescence technique and alanine-beta-CD as a model, a 1:2 guest-host complex was established, and K = 4.7 x 105 mol-2 l2 was obtained. Fluorescence enhancement was observed for all derivatives studied, with glycine exhibiting a greater enhancement, and tyrosine showing the least. The stability of the inclusion complex was found to depend on the respective sizes of the guest-host complex and their interaction.