title: Experimental and theoretical study of the inclusion complexes of 3-carboxycoumarin acid with β- and 2-hydroxypropyl-β-cyclodextrins.
abstract: The association process of a host-guest system, cyclodextrins (CyD) - 3-carboxycoumarin acid (3CCA) was followed by means of UV-vis, circular dichroism and steady-state fluorescence spectroscopies in buffer solution at pH=1. The experimental data were analyzed in order to get information on the stoichiometry, the equilibrium constants and the geometry of the inclusion complexes. In the circular dichroism spectra, a positive induced signal was obtained reflecting that the guest penetrates the cavity in such a way that the transition moment of the electronic band is quasi parallel to the host main axis. The experimental data are supported by the DFT and TDDFT (B3LYP/6-31G) calculations performed on the isolated ligand and by TDDFT (ZINDO) calculations carried out on the supramolecular ligand-cyclodextrin system.
authors.affiliation: Department of Physical Chemistry, Faculty of Chemistry, University of Bucharest, Bucharest, Romania.
authors.forename: Cristina
authors.initials: C
authors.lastname: Tablet
authors.forename: Liliana
authors.initials: L
authors.lastname: Minea
authors.forename: Luigi
authors.initials: L
authors.lastname: Dumitrache
authors.forename: Mihaela
authors.initials: M
authors.lastname: Hillebrand
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D002942:Circular Dichroism; D003374:Coumarins / Q000737:chemistry*; D008958:Models, Molecular; D013050:Spectrometry, Fluorescence; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D003374:Coumarins; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin