On the problem of reaction site in biphasic extraction of metal ions: NMR versus spectrophotometric evidence in micellar model systems

A much debated question in solvent extraction is that of the locale of the metal-extractant reaction: in the homogeneous aqueous phase or the organic/aqueous interface? Due to the existence of microscopic interfaces, micellar solutions and microemulsions can serve as model systems to try answering this question. Taking advantage of the very slow rate of complexation between an alkylated derivative of 8-hydroxyquinoline and Ni 2+ in CTAB/butanol mielles, we were able to make use of NMR as well as UV-visible spectrophotometry for kinetic investigations