This article is cited in 6 papers

ATOMS, SPECTRA, RADIATIONS

Extremely slow intramolecular vibrational redistribution: Direct observation by time-resolved Raman spectroscopy in trifluoropropyne

A. L. Malinovsky^a, A. A. Makarov^ba, E. A. Ryabov<sup>a

a</sup> Institute of Spectroscopy RAS, 142190 Troitsk, Moscow Region, Russia
^b Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region, Russia

Abstract: We have studied the dynamics of intramolecular vibrational redistribution (IVR) from the initially excited mode $\nu_1\approx3330$ cm$^{-1}$ (acetyleneṭype H–C bond) in H–C$\equiv$C–CF$_3$ molecules in the gaseous phase by means of anti-Stokes spontaneous Raman scattering. The time constant of this process is estimated as 2.3 ns – this is the slowest IVR time reported so far for the room-temperature gases. It is suggested that so long IVR time with respect to the other propyne derivatives can be explained by a larger defect, in this case, of the Fermi resonance of $\nu_1$ with $\nu_2+2\nu_7$ – the most probable doorway state leading to IVR from $\nu_1$ to the bath of all vibrational–rotational states with the close energies. In addition, it is shown that the observed dynamics is in agreement with a theoretical model assuming strong vibrational–rotational mixing.

Received: 21.12.2010

Language: English

 English version: Journal of Experimental and Theoretical Physics Letters, 2011, 93:3, 124–128

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