Affordable Access

Trajectory study of supercollision relaxation in highly vibrationally excited pyrazine and CO2.

Authors
  • Li, Ziman
  • Sansom, Rebecca
  • Bonella, Sara
  • Coker, David F
  • Mullin, Amy S
Type
Published Article
Journal
The journal of physical chemistry. A
Publication Date
Sep 01, 2005
Volume
109
Issue
34
Pages
7657–7666
Identifiers
PMID: 16834139
Source
Medline
License
Unknown

Abstract

Classical trajectory calculations were performed to simulate state-resolved energy transfer experiments of highly vibrationally excited pyrazine (E(vib) = 37,900 cm(-1)) and CO(2), which were conducted using a high-resolution transient infrared absorption spectrometer. The goal here is to use classical trajectories to simulate the supercollision energy transfer pathway wherein large amounts of energy are transferred in single collisions in order to compare with experimental results. In the trajectory calculations, Newton's laws of motion are used for the molecular motion, isolated molecules are treated as collections of harmonic oscillators, and intermolecular potentials are formed by pairwise Lennard-Jones potentials. The calculations qualitatively reproduce the observed energy partitioning in the scattered CO(2) molecules and show that the relative partitioning between bath rotation and translation is dependent on the moment of inertia of the bath molecule. The simulations show that the low-frequency modes of the vibrationally excited pyrazine contribute most to the strong collisions. The majority of collisions lead to small DeltaE values and primarily involve single encounters between the energy donor and acceptor. The large DeltaE exchanges result from both single impulsive encounters and chattering collisions that involve multiple encounters.

Report this publication

Statistics

Seen <100 times