comment on the ab initio vibrational analysis of the rotational isomers of acrolein
Y. N. Panchenko1, A. V. Abramenkov2, C. W. Bock3
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2
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Keywords: trans- and cis-acrolein, vibrational spectra, ground and lowest excited electronic states, isotopic shifts
Pages: 48-59
Abstract
Due to the publication of a number of contradictory assignments of the vibrational wave numbers of rotational isomers of acrolein in the ground electronic state, the analysis of their vibrational spectra is repeated based on the previously calculated scaled ab initio force fields. With the use of the reported results that predicted the force fields of trans-acrolein in the 1(n,π*) and 3(n, π*) states at the CASSCF/cc-pVTZ level, the experimental vibrational bands are analyzed in these excited electronic states based on well-established regularities. It is noted that in the assignment of the calculated vibrational wave numbers of the molecule, the isotopic shifts in the ground and excited electronic states 1(n, π*) and 3(n, π*) are taken into account. The previously considered calculated potential curves of the internal rotation of acrolein in combination with the data on the difference in the enthalpies (ΔH0) of conformers allow a choice to be made in favor of one of the variants of the torsional vibration wave numbers that have been reported in the literature.
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