Speaker
Description
We have revisited and enlarged the vibrational analysis of diacetyl or 2,3-butanedione by means of state-of-the-art Raman spectroscopy [1] and quantum chemical computations. The Raman spectra were obtained previously only in condensed phases [2] and hence hindered low-energy vibrational modes were undetected. Here we measured the Raman spectra of diacetyl in all the gas and liquid phases and cooled in supersonic expansions. Some new bands have been observed for the first time. Differences in the band progression and widening are discussed. The measured bands were assigned by means of density functional theory incorporating the anharmonic Generalized Vibrational Perturbative Theory of Second Order (GVPT2) correction and Born-Oppenheimer Molecular Dynamics. Discussion on the accuracy of the computational methods to describe Raman intensities and vibrational mode centers in such centrosymmetric molecule are examined.
Acknowledgement
This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 872081
[1] G. Tejeda, J. M. Fernández-Sánchez, and S. Montero. High-performance dual Raman spectrometer. Appl. Spectrosc., 51(2): 265–276, 1997.
[2] J. R. Durig, S. E. Hannum, and S. C. Brown. Vibrational spectra and structure of biacetyl. J. Phys. Chem., 75:1946–1956, 1971.
