Fourier transform ultraviolet spectroscopy of the A 2Π3/2 ← X 2II3/2 transition of BrO

The first spectra of the A (2)Pi(3/2) <-- X (2)Pi(3/2) electronic transition of BrO using Fourier transform ultraviolet spectroscopy are obtained. Broadband vibrational spectra acquired at 298 +/- 2 K and 228 +/- 5 K, as well as high-resolution rotational spectra of the A <-- X 7,0 and 12,0 vibrational bands are presented. Wavenumber positions for the spectra are obtained with high accuracy, and cross section assignments are made, incorporating the existing literature. With 35 cm(-1) (0.40 nm) resolution the absolute cross section at the peak of the 7,0 band is determined to be (1.58 +/- 0.12) x 10(-17) cm(2) molecule(-1) at 298 +/- 2 K and (1.97 +/- 0.15) x 10(-17) cm(2) molecule(-1) at 228 +/- 5 K. BrO dissociation energies are determined with a graphical Birge-Sponer technique, using Le Roy-Bernstein theory to place an upper limit on the extrapolation. From the ground-state dissociation energy, D-0" = 231.0 +/- 1.7 kJ/mol, the heat of formation of BrO(g) is calculated, Delta(f)H degrees(0 K) = 133.7 +/- 1.7 kJ/mol and Delta(f)H degrees(298.15 K) = 126.2 +/- 1.7 kJ/mol. Cross sections for the high-resolution 7,0 and 12,0 rotational peaks are the-first to be reported. The band structures are modeled, and improved band origins, rotational constants, centrifugal distortion constants, and linewidths are determined. In particular, J-dependent linewidths and lifetimes are observed for the both the 7,0 and 12,0 bands.