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

Abstract: Quantum chemical calculations have been performed on the potential energy surfaces of the two title molecules. The calculations have located the two lowest energy conformations for each molecule. For all four structures, centrifugal distortion constants and chlorine nuclear quadrupole coupling tensor components have been calculated. Analyses of the experimental rotational spectra have yielded the identification of only one conformer for each molecule. These conformers have spectroscopic constants closely matching those of the calculated lowest energy conformers. The chlorine nuclear quadrupole coupling tensor components of the title molecules have been compared with those for propionyl chloride and perfluoropropionyl chloride. [Copyright &y& Elsevier]