Time scales and pathways of vibrational energy relaxation in liquid CHBr3 and CDBr3

Title Time scales and pathways of vibrational energy relaxation in liquid CHBr3 and CDBr3
Publication Type Journal Article
Year of Publication 2006
Authors Ramesh SG, Sibert, Edwin L. III
Journal Journal of Chemical Physics
Volume 125
Date Published Dec
Accession Number ISI:000243158000029
Keywords bromoform, ch2i2, chloroform, dynamics, excitation, methanol, phase, Physics, Atomic, Molecular & Chemical, spectroscopy, Transient electronic absorption, water
Abstract Molecular dynamics simulations are used in conjunction with Landau-Teller, fluctuating Landau-Teller, and time-dependent perturbation theories to investigate energy flow out of various vibrational states of liquid CHBr3 and CDBr3. The CH stretch overtone is found to relax with a time scale of about 1 ps compared to the 50 ps rate for the fundamental. The relaxation pathways and rates for the CD stretch decay in CDBr3 are computed in order to understand the changes arising from deuteration. While the computed relaxation rate agrees well with experiments, the pathway is found to be more complex than anticipated. In addition to the above channels for CH(D) stretch relaxation that involve only the hindered translations and rotations of the solvent, routes involving off-resonant and resonant excitations of solvent vibrational modes are also examined. Finally, the decay of energy from low frequency states to near-lying solute states and solvent vibrations are studied. (c) 2006 American Institute of Physics.
Short Title J. Chem. Phys.
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