Fluorescence Quenching Investigation of the Complexes of Dibenzofuran with Natural Cyclodextrins

Applied Spectroscopy - Tập 56 Số 11 - Trang 1490-1497 - 2002
Pablo Baladrón Rodríguez1, Miguel Sánchez1, José Ramón Isasi1, Gustavo González‐Gaitano1
1Departamento de Química y Edafología. Universidad de Navarra, 31080 Pamplona, Navarra, Spain

Tóm tắt

The steady-state fluorescence of dibenzofuran (DBF) in aqueous solution is quenched in the presence of natural cyclodextrins (CDs), α, β, and γ-CD. The decrease in the fluorescence is static in nature for all the macrocycles and follows as a result of the formation of inclusion complexes of dominant 1:1 stoichiometry. With γ-CD, excimer emission is detected at high CD concentrations due to the formation of a complex of 2:2 stoichiometry, DBF2:γ-CD2. The binding constants have been determined from the fluorescence intensities through the analysis of the F0/ F vs. [CD] plots, resulting in a stronger association for β-CD. The thermodynamic parameters of the binding, enthalpy and entropy, have been calculated from the temperature dependence of the formation constants. The different trend displayed by α-CD, in both the absorption and fluorescence spectra, seems to be related to a shallow inclusion of DBF, stabilized by hydrogen bonding between the oxygen atom of the furan ring and the hydroxyl groups of CD.

Từ khóa


Tài liệu tham khảo

Szejtli J., 1988, Cyclodextrins and Their Inclusion Complexes

Duchene D., 1987, Cyclodextrins and Their Industrial Uses

Duchene D., 1991, New Trends in Cyclodextrins and Derivatives

10.1021/cr980027p

Hinze W. L., 1996, Comprehensive Molecular Chemistry (Volume 3: Cyclodextrins), 588

10.1366/0003702944027624

10.1366/0003702001949221

10.1021/j100165a053

10.1021/j100192a025

10.1021/j100400a045

10.1021/j100161a067

10.1016/0045-6535(88)90217-2

Connors K. A., 1987, Binding Constants. The Measurement of Molecular Complex Stability

10.1021/ac00267a007

10.1007/978-1-4757-3061-6

10.1007/978-94-015-7797-7

10.1246/bcsj.62.3098

10.1039/a804222e

Sbaï M., 1997, J. Fluoresc., 7, 7

10.1021/ac00184a008

10.1021/j100354a048

10.1021/j100219a030

10.1021/jp992468y

10.1246/bcsj.55.1054

10.1021/ja00319a007

Thông tin
Thông tin xuất bản

Applied Spectroscopy

Tập 56 Số 11

1490-1497

Thông tin tác giả