Search ETDs:
Vibrational Relaxation Pathways and Torsional Large Amplitude Motion Studies in the CH-Stretch Region of CH3OH and CH3OD
Twagirayezu, Sylvestre

2011, Doctor of Philosophy, University of Akron, Chemistry.
This dissertation presents spectroscopic efforts toward understanding the key impact of low-order coupling resonances and role of torsional large amplitude motion in vibrational dynamics. These efforts include a detection of rotationally resolved infrared spectra of jet-cooled CH3OH and CH3OD in the region of CH stretch fundamentals using new technique for FTMW-IR double resonance spectroscopy together with slit-jet single resonance spectroscopy (CH3OH only). The overall analysis of the observed spectra contains 17 interacting vibrational bands for CH3OD and 28 for CH3OH. The sign and magnitude of the torsional tunneling splittings are deduced for three CH stretch fundamentals (ν3, ν2, ν2) of both molecules and are compared to a model calculation and to ab initio theory. The number and distribution of observed vibrational bands indicate that the CH stretch bright states couple first to doorway states that are binary combinations of bending modes. Where doorway states are present, the observed density of coupled states is comparable to the total density of vibrational states in the molecule, but where there are no doorway states, only the CH stretch fundamentals are observed. A time-dependent dynamics of present gas phase frequency-resolved data reveals two timescales (~ 200 fs and 1-3ps) that are comparable to solution phase time-resolved data by Iwaki and Dlott.
David Perry, Dr. (Advisor)
Chrys Wesdemiotis, Dr. (Committee Member)
David Modarelli, Dr. (Committee Member)
Gujrati Purushottam, Dr. (Committee Member)
Alper Buldum, Dr. (Committee Member)

Recommended Citations

Hide/Show APA Citation

Twagirayezu, S. (2011). Vibrational Relaxation Pathways and Torsional Large Amplitude Motion Studies in the CH-Stretch Region of CH3OH and CH3OD. (Electronic Thesis or Dissertation). Retrieved from https://etd.ohiolink.edu/

Hide/Show MLA Citation

Twagirayezu, Sylvestre. "Vibrational Relaxation Pathways and Torsional Large Amplitude Motion Studies in the CH-Stretch Region of CH3OH and CH3OD." Electronic Thesis or Dissertation. University of Akron, 2011. OhioLINK Electronic Theses and Dissertations Center. 05 Jul 2015.

Hide/Show Chicago Citation

Twagirayezu, Sylvestre "Vibrational Relaxation Pathways and Torsional Large Amplitude Motion Studies in the CH-Stretch Region of CH3OH and CH3OD." Electronic Thesis or Dissertation. University of Akron, 2011. https://etd.ohiolink.edu/

Files

akron1311720280.pdf (9.23 MB) View|Download