The rate coefficients of unimolecular reactions in the systems with power-law distributions

The rate coefficient formulae of unimolecular reactions are generalized to the systems with the power-law distributions based on nonextensive statistics, and the power-law rate coefficients are derived in the high and low pressure limits, respectively. The numerical analyses are made of the rate coefficients as functions of the v-parameter, the threshold energy, the temperature and the number of degrees of freedom. We show that the new rate coefficients depend strongly on the v-parameter different from one (thus from a Boltzmann-Gibbs distribution). Two unimolecular reactions, CH3CO -> CH3 + CO and CH3NC -> CH3CN, are taken as application examples to calculate their power-law rate coefficients, which obtained with the v-parameters slightly different from one can be exactly in agreement with all the experimental studies on these two reactions in the given temperature ranges. (C) 2014 Elsevier B.V. All rights reserved.