Formation of Organosulfur Compounds from Aqueous Phase Reactions of S(IV) with Methacrolein and Methyl Vinyl Ketone in the Presence of Transition Metal Ions
Formation of Organosulfur Compounds from Aqueous Phase Reactions of S(IV) with Methacrolein and Methyl Vinyl Ketone in the Presence of Transition Metal Ions
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DOI：
10.1021/acsearthspacechem.9b00173
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发表时间：
2019-09-19
影响因子：
3.4
通讯作者：
Grassian, Vicki H.
中科院分区：
文献类型：
--
作者：
Huang, Liubin;Coddens, Ellen M.;Grassian, Vicki H.
过渡金属离子（TMIs）催化氧化S（IV）物种是水溶液硫酸盐形成的重要途径。硫氧自由基，如SO 3-、SO 4-和SO 5-自由基，是该催化反应中的主要中间体。这些自由基也可以与有机化合物反应产生有机硫化合物，这是二次有机气溶胶（SOA）形成的重要示踪剂。然而，通过这一途径形成有机硫化合物的机制还不清楚。在这里，我们调查的有机硫化合物的形成从异戊二烯氧化产物的水溶液反应，在这种情况下，甲基丙烯醛（MACR）和甲基乙烯基酮（MVK），与亚硫酸盐/亚硫酸氢盐在不同的TMI的存在下。特别是，我们在这里展示了这种化学是如何受到Fe 3+和Mn 2+单独和一起存在的影响。Fe ~（3+）和Mn ~（2+）对有机硫的形成机理有明显不同的影响。在Fe ~（3+）存在下，C_2 ~ C_4有机硫化合物及其低聚物均生成，而在Mn ~（2+）存在下，仅观察到C_2 ~ C_4有机硫化合物。当Fe 3+和Mn 2+都存在时，Fe 3+主导有机硫化合物的形成，如即使在Fe 3+与Mn 2+的低比例（1：25）下观察到的低聚物的显著增加所示。此外，有机硫化合物的定量表明，有机硫化合物的形成，通过三甲基碘甲烷催化的反应作出了显着的贡献的命运S（IV）在水相中。这些反应在大气中的重要性进行了讨论。
The catalytic oxidation of S(IV) species by transition metal ions (TMIs) is a significant pathway for aqueous sulfate formation. Sulfoxy radicals, such as SO3-, SO4-, and SO5- radicals, are major intermediates in this catalytic reaction. These radicals can also react with organic compounds to produce organosulfur compounds, which are important tracers of secondary organic aerosol (SOA) formation. However, the mechanism for the formation of organosulfur compounds via this pathway is not well understood. Here, we investigate the formation of organosulfur compounds from the aqueous reaction of isoprene oxidation products, in this case, methacrolein (MACR) and methyl vinyl ketone (MVK), with sulfite/bisulfite in the presence of different TMIs. In particular, we show here how this chemistry is influenced by the presence of Fe3+ and Mn2+ both separately and together. Fe3+ and Mn2+ have distinctly different effects on the mechanism for organosulfur formation. Both C-2-C-4 organosulfur compounds and their oligomers are formed in the presence of Fe-3(+), whereas only C-2-C-4 organosulfur compounds are observed in the presence of Mn2+. Fe3+ dominates the formation of organosulfur compounds when both Fe3+ and Mn2+ are present, as indicated by the significant increase of oligomers observed even at low ratios of Fe3+ to Mn2+ (1:25). Furthermore, the quantification of organosulfur compounds shows that organosulfur compound formation through TMI-catalyzed reactions makes a significant contribution to the fate of S(IV) in the aqueous phase. The importance of these reactions in the atmosphere is discussed.