Calculated and experimental rotational spectra of 3,3,3-trifluoro- and 2,2,3,3-tetrafluoropropionyl chloride

Methyl group internal rotation and the choice of Hamiltonian for the rotational spectrum of 1,1-difluoroacetone

“…Although this is not the first report of an extreme sensitivity to the choice of the reduction, see for example Ref. [21], it may be the first report of this phenomenon where (1) the context of the analysis is an internal rotation problem and/or (2) where only the five independent quartic centrifugal distortion terms are required in the effective reduced Hamiltonian.…”

“…Spectroscopic examinations of partially fluorinated compounds, when taken as part of a series, allow for geometric and electronic structural differences between fully fluorinated and non-fluorinated organic frameworks to be tracked as functions of the number of fluorines present in the system, see for example Refs. [1,2].…”