High-resolution spectroscopy of H2SO4, HDSO4, and D2SO4 vapor in the region 1200-10,000 cm−1

The high-resolution (0.05 cm−1) spectra of gas-phase H2SO4, HDSO4, and D2SO4 were measured over the frequency region 1200-10,000 cm−1 using Fourier-transform infrared spectroscopy. The increased resolution of this work compared with previous studies has lead to an improved vibrational analysis of H2SO4. This study has answered unresolved questions about combination bands and overlapping features from previous gas-phase spectroscopic studies of H2SO4 and marks the first experimental measurement of the ν8 and ν15 torsional vibrations in this molecule. This work leads to a brief discussion on vibrational mode mixing in sulfuric acid.