Microwave spectrum of the BrO radical equilibrium structure and dipole moment

The J = {5}/{2} ← {3}/{2} transitions of the BrO radical in the first excited vibrational level of the ²Π_{3}/{2} ground electronic state have been observed and analyzed by taking into consideration the hyperfine matrix elements off-diagonal in J. The ground-state spectra were also reanalyzed in the same way, and the equilibrium internuclear distance was determined to be r _e = 1.717 ₁ ± 0.0013 Å. The dipole moment of the ²Π_{3}/{2} state was calculated from the Stark effects to be 1.76 ₅ ± 0.023 and 1.79 ₄ ± 0.049 D for ⁷⁹BrO and ⁸¹BrO, respectively, in the ground vibrational state.