The hyperfine structure in the rotational spectra of bromofluoromethane: Lamb-dip technique and quantum-chemical calculations

Abstract

The hyperfine structure in the rotational spectra of six isotopic species of bromofluoromethane, namely CH2 79BrF, CH2 81BrF, CDH79BrF, CDH81BrF, CD2 79BrF and CD2 81BrF, has been investigated using the Lamb-dip technique in the submillimeter-wave frequency range. Measurements and assignment procedures were supported by high-level quantum-chemical calculations of the hyperfine parameters at the coupled-cluster level. For all species, the accuracy of the determined rotational and centrifugal distortion constants and the bromine quadrupole-coupling constants were improved with respect to available literature data, whereas the full bromine quadrupole-coupling tensor for the monodeuterated species and the bromine spin–rotation constants for all isotopologues were determined for the first time.