The Mechanisms, Kinetics and Thermodynamics of the Gas-phase Pyrolysis of sec-butyl Bromide: A Computational Approach
Omolara, Olubunmi Adeboye *
Department of Chemistry, Emmanuel Alayande College of Education, P.M.B. 1010, Oyo, Nigeria
*Author to whom correspondence should be addressed.
Abstract
The mechanisms, kinetics and thermodynamics of the gas-phase pyrolysis of sec-butyl bromide at 623K was carried out using Density Functional Theory (DFT) with B3LYP at 6-311++G (2df, 2p) level method. The result showed that the pyrolysis of sec-butyl bromide proceeds through a four-membered cyclic transition state which involved a C10-H11 and C8-Br14 bond breaking and Hx-Br14 (Hx= H11, H6 and H7 for n-butene, trans and cis-2-butene) bond making. The calculated data [∆H* (179.28, 178.96 and 181.83 kJ/mol), Ea (184.46, 184.15 and 187.01 kJ/mol), logA (13.73, 13.11 and 13.67)] obtained are closer to experimental results [∆H* (178.19, 185,31 and 189.50kJ/mol), Ea (183.38, 190.49 and 194.68 kJ/mol), logA (12.60, 13.10 and 13.50) for n-butene, trans-2-butene and cis-2-butene respectively].
Keywords: Density functional theory calculation, sec-butyl bromide, gas-phase, kinetics