Dynamics of the cis–trans isomerization and Cl–O dissociation of chlorine nitrite. Classical trajectory and statistical calculations

Abstract

The dynamics of the cis–trans isomerization and Cl–O dissociation of chlorine nitrite were explored by classical trajectories and Monte Carlo variational transition state theory. Ab initio calculations were performed to obtain structural data for the ground-state potential energy surface (PES) of ClONO. The results were used to construct an analytical PES to be employed in the dynamics study. Under microcanonical initial conditions, the classical trajectory simulations predict that chlorine nitrite exhibits intrinsic non-RRKM behavior at the energies investigated. In addition, under non-random initial conditions, the system presents strong specific effects. In particular, excitation of the NO stretch led to few reactive trajectories, indicating that this mode is a bottleneck for intramolecular vibrational redistribution (IVR). Finally, the results suggest that vibrational–rotational coupling is insignificant, except for rotational excitation around the a-axis in the trans-isomer.