title: Solvent effects on the thermodynamics and kinetics of coralyne self-aggregation.
abstract: The role of solvent effects on the thermodynamics and kinetics of the coralyne self-aggregation process has been investigated in ethanol-water mixtures of different compositions. The changes in the UV/visible spectra of coralyne and FAB/LSIMS mass spectrometry agreed well with the formation of a dimer species. 1D and 2D 1H experiments have allowed one to look into the features of the self-aggregation process and to determine the equilibrium constant and the deltaH0 and deltaS0 values for the aggregate formation in 0-50% ethanol-water mixtures. The kinetics of self-aggregation has been investigated by the T-jump chemical relaxation method, and the results have been interpreted in terms of dimer formation. The dependence of the relative viscosity of coralyne solutions on the dye concentration was studied in different ethanol-water mixtures. Finally, it was found that coralyne behaves as a solvatochromic indicator which is preferentially solvated according to the sequence ethanol > ethanol-water > water. All of the results concur in elucidating the relevant role of the hydrophobic interaction process of coralyne stack formation.
authors.affiliation: Departamento de Química, Universidad de Burgos, 09001 Burgos, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: García
authors.forename: Saturnino
authors.initials: S
authors.lastname: Ibeas
authors.forename: Rebeca
authors.initials: R
authors.lastname: Ruiz
authors.forename: Jose M
authors.initials: JM
authors.lastname: Leal
authors.forename: Tarita
authors.initials: T
authors.lastname: Biver
authors.forename: Alessia
authors.initials: A
authors.lastname: Boggioni
authors.forename: Fernando
authors.initials: F
authors.lastname: Secco
authors.forename: Marcella
authors.initials: M
authors.lastname: Venturini
mesh_terms: D001600:Berberine Alkaloids / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D012997:Solvents / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D001600:Berberine Alkaloids; D012997:Solvents; C000666:coralyne