Abstract:
Modifications to a pressure-jump autoclave are described which permit the measurement of rapid rates of reaction in aprotic solvents. In such solvents, a chemical system at equilibrium will generally be perturbed primarily by the temprature decrease which accompanies the adiabatic expansion process. The factors which determine the amplitude of the resulting relaxation transient are discussed, and kinetic data are reported for the fast proton-transfer reaction between the phenolic indicator acid bromophenol blue and the weak base pyridine in chlorobenzene and 1,2-dichlorobenzene. Results obtained by means of the pressure-jump method are in excellent agreement with those obtained using other fast reaction techniques.
