Concerning the electronic and geometric structure of bromodifluoroacetonitrile, CBrF2CN

The pure rotational spectrum of bromodifluoroacetonitrile between 7.7 and 18 GHz has been measured on a chirped pulse microwave spectrometer. The spectra are dense with 889 measured transitions in the region. Rotational, centrifugal distortion, nuclear electric quadrupole coupling constants (79Br, 81Br, and 14N), and nuclear magnetic spin-rotation constants (79Br/81Br) were determined and are reported for the first time. Quantum chemical calculations were made of the nuclear quadrupole coupling constants to assist with assignment of the spectra. Spectra from both 13C isotopologues were measured in natural abundance. The effects of flourination on the nuclear electric quadrupole coupling tensor components for the series of monobrominated acetonitrile molecules are discussed.