Computational Modelling of the Mechanisms, Kinetics and Thermodynamics of Pyrolysis of Isobutyl Bromide in the Gas-phase

The kinetics, mechanisms and thermodynamics of the gas-phase pyrolysis of isobutyl bromide at 623 K was carried out using Density Functional Theory modelling with B3LYP at 6-311++G (2df, 2 p) level method of calculation. Calculations showed that the reaction is a unimolecular reaction and the pyrolytic reaction proceeds through a four-centered cyclic transition state that involved a C1-H2 and C3-Br9 bond breaking and H2-Br9 bond making. The calculated data [∆Hreaction(48.08 kJ/mol), ∆H* (205.35 kJ/mol), Ea (210.35 kJ/mol), log A (13.86), rate, k (1.67 x 10-4 s-1)] obtained at 623 K are in agreement with experimental calculated results at 693 K [∆Hreaction(58.61 kJ/mol), ∆H*(204.83 kJ/mol), Ea (211.01 kJ/mol), log A(13.10), rate, k (1.52 x 10-4 s-1)] results.