The intramolecular dynamics of Cl-- - -CH3Br complexes is studied at an energy approximately equal to the average thermal energy of complexes formed by Cl- + CH3Br association at 300 K. Lyapunov exponents are calculated for different mode excitations of the Cl-- - -CH3Br complex. Without zero-point energy added to the complex, a number of the mode excitations have zero Lyapunov exponents and, thus, regular motion. The Lyapunov exponents are positive and the motion is chaotic for all mode excitations with zero-point energy added. However, the latter Lyapunov exponents are sufficiently small that the time required to form a microcanonical ensemble of Cl-- - -CH3Br states is much longer than the RRKM lifetime of the complex. Thus, non-RRKM unimolecular dynamics is expected for the Cl-- - -CH3Br complex as found in previous trajectory simulations.
|Number of pages||13|
|Journal||International Journal of Mass Spectrometry and Ion Processes|
|State||Published - 1997|