The reactivity of p-nitrophenyl esters with surfactants in nonaqueous solvents. IV. p-Nitrophenyl acetate in benzene solutions of dodecylammonium phenoxides

Abstract

The rate of decomposition of p-nitrophenyl acetate, pnpa, has been measured at 298 K in benzene solutions of a series of dodecylammonium 4-substituted phenoxide salts, CH₃(CH₂)₁₁NH₃⁺ -OC₆H₄X-p (where X = H, Cl, Br, Me or MeO). Absorbance measurements indicate that aggregation of these compounds occurs at concentrations greater than 10^-4 mol dm^-3 in benzene. The observed rate constants of aminolysis are affected by the basicity of the phenol. In the presence of solubilized water the rate of decomposition of pnpa is increased slightly due to an increase in the effective concentration of the free amine and due to the occurrence of hydrolysis. The effect of an increase in temperature and of a change in solvent (to toluene) has been studied.