Theoretical study on the reaction of bromine-substituted ethanes with hydrogen atoms

The mechanism of the multi-channel reaction H + CH3CH2Br is studied by QCISD(T)/6-311+G(2df, 2p)//BH&H-LYP/6-311G(d, p) level. The rate constants are evaluated using canonical variational transition state theory (CVT) with a small-curvature tunneling correction (SCT) over a range of temperatures 220–2000 K. The calculations show that in the four reaction channels, i.e., bromine-, α-hydrogen and two β-hydrogen abstractions, the bromine abstraction channel is most prominent and hydrogen abstraction channels appear to be probable only at high temperatures. Agreement between theory and experiment is good.