Study on partition equilibria of metal complexes in non-ionic micellar solutions from spectrophotometric data

The complexation equilibria for Zn(II)–8-quinolinol and Zn(II)–5,7-dichloro-2-methyl-8-quinolinol systems were studied spectrophotometrically in aqueous micellar solutions of the non-ionic surfactant Brij-35 in NaCl 0.1 M medium at 25°C. The partition model, in which the different species involved in the equilibria can distribute themselves between aqueous and micellar pseudophases, was applied. Calculations were performed by means of the spdis program, developed specifically to handle multiwavelength spectrophotometric data in micellar systems. A factor analysis was applied to the spectrophotometric data in order to determine the number of species in equilibrium. A quantitative relationship was found between fluorescence intensity and the micellar solubilization of metal chelates.