Effect of SDS micelles on the reactivity of 4 '-methoxyflavylium ion: A stopped-flow and photochemical study

The network of chemical reactions of the compound 4'-methoxyflavylium was studied in the presence of SDS micelles, using stopped-flow, UV-vis absorption and flash photolysis techniques. The results were compared with analogous experiments carried out in water. The large stabilization of the flavylium cation onto the micelles was proven to be due to an increase in the rate of the dehydration reaction, rather than a decrease of the hydration reaction; the cis-trans isomerisation of the chalcone was not affected by the micelles. It is shown that SDS micelles can be considered as an external stimulus capable of changing the system from one state to another. (c) 2006 Elsevier B.V. All rights reserved.