The Influence of a Nearly Free Methyl Rotor on the Dynamics of Vibrational Predissociation and IVR

  • Z.-Q. Zhao
  • C. S. Parmenter
Part of the Springer Proceedings in Physics book series (SPPHY, volume 68)


Intramolecular vibrational redistribution (IVR) rates can be profoundly changed by simple chemical modifications. An example occurs in the molecular pair p-difluorobenzene (pDFB) and p-fluorotoluene (pFT). These molecules are related by the replacement of a pDFB fluorine with a methyl group to produce pFT. IVR in 300 K gas phase molecules has been characterized for regions of the S1 manifold where the ring mode density is 100–2000 states per cm−1 [1,2]. The methyl substitution increases IVR rates by about a hundred-fold [2]. The time scales change from 15–300 psec to sub-psec.


Internal Rotation Ring Mode Fluorescence Excitation Spectrum Methyl Substitution Coupling Matrix Element 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    K.W. Holtzclaw and C.S. Parmenter, J. Chem. Phys. 84, 1099 (1986).ADSCrossRefGoogle Scholar
  2. [2]
    C.S. Parmenter and B.M. Stone, J. Chem. Phys. 84, 4710 (1986).ADSCrossRefGoogle Scholar
  3. [3]
    H.-K. O, Ph.D. Thesis, Indiana University, 1990.Google Scholar
  4. [4]
    K. Okuyama, N. Mikami and M. Ito, J. Phys. Chem. 89, 5617 (1985).CrossRefGoogle Scholar
  5. [5]
    D.B. Moss, C.S. Parmenter, and G.E. Ewing, J. Chem. Phys. 86, 51 (1987).ADSCrossRefGoogle Scholar
  6. [6]
    Z.-Q. Zhao and C.S. Parmenter, “Proceedings of the 24th Jerusalem Conference in Quantum Chemistry and Biochemistry”, B. Pullman and J. Jortner, Editors. (Kluwer Academic Publishers, Dordrecht, 1991), (in press).Google Scholar
  7. [7]
    H.D. Rudolph and H. Seiler, Z. Naturforsch. 20, 1682 (1965).ADSGoogle Scholar
  8. P.N. Ghosh, J. Mol. Spectrosc. 138, 505 (1989).ADSCrossRefGoogle Scholar
  9. P.N. Ghosh, J. Mol. Spectrosc., 142, 295 (1990).ADSCrossRefGoogle Scholar
  10. [8]
    K.W. Butz, D.L. Catlett, Jr., G.E. Ewing, D. Krajnovich, and C.S. Parmenter, J. Phys. Chem., 90, 3522 (1986).CrossRefGoogle Scholar
  11. [9]
    H.-K. O, C.S. Parmenter, and M.-C. Su, Ber. Bunsenges. Phys. Chem. 92, 253 (1988).Google Scholar
  12. [10]
    A.R. Tiller, A.C. Peet and D.C. Claiy, Chem. Phys. 129, 125 (1989).CrossRefGoogle Scholar
  13. [11]
    P.M. Weber and S.A. Rice, J. Chem. Phys. 92, 5470 (1988).CrossRefGoogle Scholar
  14. [12]
    D.F. Kelley and E.R. Bernstein, J. Phys. Chem. 90, 5164 (1986).CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1992

Authors and Affiliations

  • Z.-Q. Zhao
    • 1
  • C. S. Parmenter
    • 1
  1. 1.Department of ChemistryIndiana UniversityBloomingtonUSA

Personalised recommendations