The gas phase characterization of perfluorobutyryl chloride, C3F7COCl, using chirped pulse Fourier transform microwave spectroscopy

A chirped pulse Fourier transform microwave spectrometer has been used to record the pure rotational spectrum of perfluorobutyryl chloride seeded in a pulsed supersonic expansion of argon gas. Only one conformer of the title molecule was observed. For the 35Cl species a total of 236 spectral transitions were recorded. Quantum chemical calculations together with the spectral constants obtained indicate that the observed conformer has the CCCCOCl centers contained within the ab plane with a dihedral angle ∠CCCO = 0°.