Infrared spectroscopy of SO2 aqueous solutions

The chemistry of SO2 solutions was studied with infrared transmission and total internal reflection (ATR) spectroscopy. The cross-sections of the SO2 Stretching vibrations nu(1), nu(3) and the combination band of nu(1) + nu(3) were obtained and found to be slightly different from their gas phase values. Six features we associate with sulfur-containing ions were observed. We present the first infrared evidence for the bisulfite ion HOSO2- through detection of its OH stretching vibration. Other features may be associated with HSO3-, another isomer of the bisulfite ion, and a new compound we propose to be H2S2O62-. We found no evidence for sulfurous acid H2SO3. (C) 2002 Elsevier Science B.V. All rights reserved.