Kinetic Study of the Reaction of Leuco Methylene Blue with 2,6-Dimethyl-<Emphasis Type="Italic">p</Emphasis>-benzoquinone in a Reverse Micellar System

The kinetics of the reaction of leuco methylene blue (MBH) with 2,6-dimethyl-p-benzoquinone (DMBQ) were studied in a heptane/bis(2-ethylhexyl)-sulfosuccinate (AOT)/water reverse micellar system. The pseudo-first-order rate constant (k _obsd) obtained in the presence of excess of DMBQ was found to be proportional to the initial concentration of DMBQ for W ₀=3, 5, 10, 15 and 20 (W ₀=H₂O]/AOT]). The second-order rate constant (k ₂=k _obsd/DMBQ]₀) increased with an increase in the W ₀ value, but was almost independent of the concentration of the water pool. A mechanism involving the distribution of DMBQ between the reverse micellar interface and bulk organic solvent was proposed to explain these findings.