Frankfurt 2006 – scientific programme
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MO: Molekülphysik
MO 14: Ultrafast IR and Raman Probe and Control
MO 14.6: Talk
Monday, March 13, 2006, 17:45–18:00, H12
Ultrafast Dynamics of Molecules Exhibiting Double Minimum Potential — •A.V. Scaria, J. Konradi, A.K. Singh, and A. Materny — International University Bremen, Germany
Femtosecond time-resolved four-wave mixing (FWM) spectroscopy is a powerful technique for observing ultrafast molecular dynamics. Studies are carried out on molecules exhibiting double minimum potential structure in gas phase and in liquid phase using different FWM techniques. Of particular interest among them are e.g. molecules showing ring puckering vibrations (characteristic for cyclic molecules having -CH2-, -O- or -S- groups). Ring puckering vibrations involve the bending motions of the group out of the plane of the ring. The potential energy curve for the vibration shows, therefore, two (nearly) identical minima corresponding to the ring being puckered upwards or downwards. Investigations are carried out on Trimethylene Sulfide (TMS) and Trimethylene Oxide (TMO) having barrier heights of 274 and 15 cm−1, respectively. The time-resolved techniques applied are femtosecond degenerate four-wave mixing (DFWM) and coherent anti-Stokes Raman scattering (CARS). The observed dynamics of these vibrational modes obtained from gas and liquid phase will be presented and discussed in comparison with each other.