Journal of Physical Chemistry A, Vol.102, No.8, 1292-1296, 1998
Role of state specificity in the temperature- and pressure-dependent unimolecular rate constants for HO2 -> H+O-2 dissociation
Recent quantum dynamical calculations have shown that HO2 dissociates via isolated resonances, which have a distribution of rate constants that is statistical state-specific and well-described by the Porter-Thomas P-E(k) distribution. In the work presented here, this P-E(k) distribution is incorporated into RRKM theory to see how statistical fluctuations in state-specific rate constants affect the collision-averaged chemical activation rate constant k(omega, E) and the Lindemann-Hinshelwood thermal rate constant k(uni)(omega, T) for HO2 dissociation. Both active and adiabatic treatments are considered for the K quantum number. The calculations suggest the effect of statistical state specificity should be detectable in measurements of k(omega, E) and k(uni)(omega, T).
Keywords:MULTIPLE TRANSITION-STATES;SHOCK-TUBE;OVERLAPPING RESONANCES;CHEMICAL-REACTIONS;ANGULAR-MOMENTUM;RATE COEFFICIENT;HEH2+ SYSTEMS;RRKM THEORY;REACTION H;HO2