Computational Study of Gas-Phase Reactions to Produce Sulfite Esters: A New Class of Sulfur Containing Molecules in the Atmosphere?

Abstract

Abstract We use computational quantum chemistry to study gas-phase reactions of aldehydes with water and sulfur dioxide. We find that a new reaction leading to the formation of previously nearly unstudied sulfite esters is possible with a comparatively low barrier. The reaction can be catalyzed by the presence of additional hydrogen bonding molecules, including water, nitric acid, and sulfuric acid. Our calculations also show that the binding energy between nitrate ions and sulfite esters should be high enough to enable their detection by nitrate ion chemical ionization mass spectrometry (CIMS). Under certain conditions, such as at the surface of acid–base clusters, the formation of these sulfite esters should be competitive with that of organosulfates and sulfinic acids. These findings suggest that sulfite esters may represent a new class of molecules that can contribute to new particle formation (NPF) and the subsequent generation of atmospheric aerosol.