HR: 0830h
AN: A21E-1020    [PDF]
TI: Vibrational Spectroscopy of Sodium Halide and Hydrogen Halide Aqueous Solutions: Application to Atmospheric Aerosol Chemistry
AU: * Levering, L M
EM: lleverin@chemistry.ohio-state.edu
AF: The Ohio State University, Dept. of Chemistry 100 W. 18th Ave., Columbus, OH 43210 United States
AU: Liu, D
EM: dliu@chemistry.ohio-state.edu
AF: The Ohio State University, Dept. of Chemistry 100 W. 18th Ave., Columbus, OH 43210 United States
AU: Allen, H C
EM: allen@chemistry.ohio-state.edu
AF: The Ohio State University, Dept. of Chemistry 100 W. 18th Ave., Columbus, OH 43210 United States
AB: Heterogeneous reactions on the surfaces of atmospheric aerosols play an important role in atmospheric chemistry. These reactions are capable of converting alkyl and hydrogen halides (common constituents of marine boundary aerosols) into active halogen compounds. Fundamental questions still remain concerning surface species and reaction mechanisms pertaining to marine boundary aerosols. The first step in beginning to understand these heterogeneous reactions is to determine how ions in solution affect the structure of water at the interface. Vibrational sum frequency generation spectroscopy is used to examine the air-liquid interface of sodium halide and hydrogen halide (i.e. strong acid) solutions. In addition, comparison of the bulk water structure to that of the interface is accomplished using Raman spectroscopy. The hydrogen-bonding environment at the surface of NaCl is found to be similar to that of the air-water interface. In contrast, the interfacial water structure of NaBr, HCl, and HBr solutions is significantly altered from that of neat water. In the bulk, NaCl, NaBr, HCl, and HBr solutions disturb the hydrogen-bonding network of neat water. A comparison between the corresponding salts and acids show that the salts produce greater disorder (i.e. less coupling of the water symmetric stretching modes) in the bulk water structure.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0320 Cloud physics and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting