Intramolecular vibrational dynamics of ν1 mode in (CF3)2C=C=O molecule induced by resonant IR femtosecond radiation

Abstract

Intramolecular dynamics of the vibrational levels (up to v = 5) of the ν1 mode in (CF3)2CCO molecule, induced via multiphoton selective excitation of this mode by resonant femtosecond IR radiation, was studied. The times of intramolecular vibrational energy redistribution (IVR) of each vibrational level v to the remaining modes of the molecule were measured. In accordance with the theory predictions the decrease of IVR time with increasing v is observed. A sharp reduction of the IVR time (up to 1 ps) at a wavelength of 2130 cm−1 of transition v=3 → v=4 was found. It was shown that with a negative chirp of a femtosecond radiation pulse the population of high-lying vibrational levels of ν1 modes significantly increases.