Microwave spectrum, quadrupole coupling constants, and structure of N–bromodifluoromethanimine

Abstract

A continuous flow system has been used to measure the microwave spectrum (26.5 to 40.0 GHz) of rapidly decomposing N–bromodifluoromethanimine, CF2=NBr. The hyperfine structure of the spectrum caused by two nuclei with nuclear quadrupole moments (14N,79Br, or 81Br) has been analyzed and rotational, centrifugal distortion, and quadrupole coupling constants have been determined by a global least-squares fit for both bromine isotopic species. Identification and assignment of R transitions in the b-type spectrum have been facilitated considerably by the determination of the magnitude of the rotational constants from the hyperfine structure of the Q transitions alone. A structure compatible with the observed rotational constants has been determined for this planar molecule.