Computational study on the radical reaction C4H + C4H10

The first theoretical study of the radical reaction C4H + C4H10 is presented. The geometries and harmonic vibrational frequencies of all the stationary points are obtained at the MP2/6-311G** level of theory. Three hydrogen abstraction channels are identified and the minimum energy paths (MEPs) are presented in the work. The calculated results reveal that there exists a reactant complex for each hydrogen abstraction channel which exhibits the nature of van der Waals complex. A dual-level direct dynamics method is employed to calculate the rate coefficients of the title reaction. The rate coefficients for all the reaction channels are evaluated in the temperature range of 200–500 K using the conventional transition state theory and the variational transition state theory. The branching ratio of the title reaction is plotted and the calculated results illustrate that reaction channel R3 contributes the most part to the overall reaction. The comparison between theoretical and experimental results is discussed and exhibits best agreement. The fitted three-parameter Arrhenius expression of the rate coefficients for the reaction is provided for the convenience of future experimental measurement.