Vibrational energy relaxation of the bend fundamental of dilute water in liquid chloroform and d-chloroform

Journal Article (Journal Article)

The population lifetimes of the bend fundamental of dilute water in liquid chloroform (8.5 ps) and d-chloroform (28.5 ps) display an interesting solvent isotope effect. As the lowest excited vibrational state of the molecule, the water bend fundamental relaxes directly to the ground state with about 1600 cm-1 of energy released to the other degrees of freedom. The strong solvent isotope effect along with the large energy gap indicates the participation of solvent vibrational modes in this vibrational energy relaxation process. We calculate the vibrational energy relaxation rates of the water bend in chloroform and d-chloroform using the Landau - Teller formula with a new potential model developed and parametrized self-consistently to describe the chloroform - water interaction. The computed values are in reasonable agreement with the experimental results, and the trend for the isotope effect is correct. It is found that energy transfer to the solvent vibrations does indeed play an important role. Nevertheless, no single dominant solvent accepting mode can be identified; the relaxation appears to involve both the bend and the C-Cl stretches, and frequency changes of all of these modes upon deuteration contribute to the observed solvent isotope effect. © 2008 American Chemical Society.

Full Text

Duke Authors

Cited Authors

  • Lin, YS; Ramesh, SG; Shorb, JM; Sibert, EL; Skinner, JL

Published Date

  • January 17, 2008

Published In

Volume / Issue

  • 112 / 2

Start / End Page

  • 390 - 398

International Standard Serial Number (ISSN)

  • 1520-6106

Digital Object Identifier (DOI)

  • 10.1021/jp075682s

Citation Source

  • Scopus