Rate constant for the NH3 + NO2 → NH2 + HONO reaction: Comparison of kinetically modeled and predicted results

The rate constant for the NH₃ + NO₂ rlhar2; NH₂ + HONO reaction (1) has been kinetically modeled by using the photometrically measured NO₂ decay rates available in the literature. The rates of NO₂ decay were found to be strongly dependent on reaction (1) and, to a significant extent, on the secondary reactions of NH₂ with NO_X and the decomposition of HONO formed in the initiation reaction. These secondary reactions lower the values of k₁ determined directly from the experiments. Kinetic modeling of the initial rates of NO₂ decay computed from the reported rate equation, - dNO₂]/dt = k₁NH₃]NO₂] based on the conditions employed led to the following expression: This result agrees closely with the values predicted by ab initio MO G2M//B3LYP/6-311 G(d,p)] and TST calculations. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 245–251, 1997.