Organosulfate and nitrate formation and reactivity from epoxides derived from 2-methyl-3-buten-2-ol.

Recent work has suggested that 2-methyl-3-butene-2-ol (MBO)-derived epoxide intermediates are responsible for some of the molecular species commonly found in ambient secondary organic aerosol (SOA). Nuclear magnetic resonance techniques were used to study the reaction kinetics and products of two potential MBO-derived epoxides under acidic solution conditions in the presence of sulfate and nitrate nucleophiles. These epoxides were found to undergo reasonably fast acid-catalyzed reaction at typical SOA acidities and to produce a variety of organosulfate and nitrate species. This finding supports a previous supposition that 3-methylbutane-1,2,3-triol and at least some of the MBO-derived organosulfates previously detected on SOA are formed from the reactions of these epoxides. In general, the particular MBO-derived organosulfates and nitrates produced from MBO-derived epoxides and their respective stability toward hydrolysis were similar to those found for isoprene-derived epoxides; the nucleophilic reactions were observed to be quite regiospecific, and the tertiary addition product species were found to hydrolyze on atmospherically relevant time scales.