A kinetic study of the formation and dissociation of the Meisenheimer complex formed between 1,3,5-trinitrobenzene and the hydroxide ion in micellar dodecyltrimethylammonium bromide solution

Abstract

The rates of formation and dissociation of the thermoaddition complex of 1,3,5-trinitrobenzene with OH^– has been investigated in micellar solutions of dodecyltrimethylammonium bromide (DTABr) using a stopped-flow spectrometer. We have observed and measured three processes which proceed under different conditions of acidity: (a) formation of the σ complex, (b) spontaneous (equilibrium) dissociation in less basic solutions and (c) dissociation via proton attack in acid solutions. These processes are influenced by the background KBr electrolyte. The interphase potential Δϕ=ϕ_m–ϕ_w, depicted in the pseudophase model, allows us to explain the variations of the rate constants.