Microwave Spectrum of BrCN and Dependence of Quadrupole Coupling Constant on the Vibrational State

Abstract
The hyperfine structure of the J=1←0 and J=2←1 rotational transitions of BrCN has been measured. The values of eqQ(Br 79 ) and eqQ(Br 81 ) for each vibrational state were obtained as follows.