Quantum Mechanical Study of the Kinetics, Mechanisms and Thermodynamics of the Gas-Phase Pyrolysis of Isopropyl Bromide

Abstract

Computational studies of the kinetics, mechanisms and thermodynamics of the gas-phase pyrolysis of isopropyl bromide at 623K was studied using PM3 in the semi-empirical and DFT with B3LYP at 6-31G* level methods of calculation. The reaction proved to be a unimolecular reaction and followed a first order rate equation. The calculation showed that the pyrolysis of isopropyl bromide proceeds through a four-membered cyclic transition state which involved a C₈-H₁₁ and C₄-Br₆ bond breaking and H₁₁-Br₆ bond making. The Arrhenius parameters, log A (13.6 and 13.8) obtained for both methods are in good agreement with experimental result (13.6).

Keywords: semi-empirical, isopropyl bromide, gas-phase, kinetics.