Collisional Intermolecular Energy Transfer from a N 2 Bath at Room Temperature to a Vibrationlly "Cold" C 6 F 6 Molecule Using Chemical Dynamics Simulations

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Vol. 121; no. 21; pp. 4049 - 4057
• Main Authors: Paul, Amit K, Donzis, Diego, Hase, William L
• Format: Journal Article
• Language: English
• Published: United States 01-06-2017
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/acs.jpca.7b00948

Chemical dynamics simulations were performed to study collisional intermolecular energy transfer from a thermalized N
bath at 300 K to vibrationally "cold" C
F
. The vibrational temperature of C
F
is taken as 50 K, which corresponds to a classical vibrational energy of 2.98 kcal/mol. The temperature ratio between C
F
and the bath is 1/6, the reciprocal of the same ratio for previous "hot" C
F
simulations (J. Chem. Phys. 2014, 140, 194103). Simulations were also done for a C
F
vibrational temperature of 0 K. The average energy of C
F
versus time is well fit by a biexponential function which gives a slightly larger short time rate component, k
, but a four times smaller long time rate component, k
, compared to those obtained from the "hot" C
F
simulations. The average energy transferred per collision depends on the difference between the average energy of C
F
and the final C
F
energy after equilibration with the bath, but not on the temperature ratio of C
F
and the bath. The translational and rotational degrees of freedom of the N
bath transfer their energies to the vibrational degrees of freedom of C
F
. The energies of the N
vibrational mode and translational and rotational modes of C
F
remain unchanged during the energy transfer. It is also found that the energy distribution of C
F
broadens as energy is transferred from the bath, with an almost linear increase in the deviation of the C
F
energies from the average C
F
energy as the average energy of C
F
increases.