A microwave and computational study of trifluoroacetic anhydride

The microwave spectrum of trifluoroacetic anhydride (CF3COOCOCF3) has been recorded by chirped-pulse and cavity Fourier transform microwave spectroscopy. A dense b-type spectrum containing several P, Q and R branch progressions has been assigned and fit to the Watson A-reduced asymmetric rotor Hamiltonian. No evidence of tunneling or internal rotation of the CF3 groups was observed. DFT calculations of the rotational constants are in good agreement with experimental results. (C) 2019 Elsevier Inc. All rights reserved.