Uncovering a new class of reactions in the atmosphere: SN2-type substitution reactions of nitrogen oxides and seawater

McCaslin, Laura M.

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https://hdl.handle.net/2142/104303 Copy

Description

Title

Uncovering a new class of reactions in the atmosphere: SN2-type substitution reactions of nitrogen oxides and seawater

Author(s)

McCaslin, Laura M.

Contributor(s)

• Gerber, R. Benny
• Johnson, Mark

Issue Date

2019-06-18

Keyword(s)

Non-covalent interactions

Abstract

Recent studies indicate that nitrogen oxide species in the atmosphere, including N$_2$O$_5$ and ONONO$_2$, undergo a new class of S$_N$2-type substitution reactions when in contact with seawater and sea spray aerosols.\footnote{P. J. Kelleher, F. S. Menges, J. W. DePalma, J. K. Denton, M. A. Johnson, G. H. Weddle, B. Hirshberg, R. B. Gerber, \textit{J. Phys. Chem. Lett.} \textbf{8}, 4710 (2017).}$^,$\footnote{R. B. Gerber, L. McCaslin, N. V. Karimova, \textit{Faraday Discuss.} (Accepted).}$^,$\footnote{L. M. McCaslin, M. A. Johnson, R. B. Gerber, (In review)} The reactions of atmospheric nitrogen oxides with seawater play many integral roles in regulating levels of O$_3$, OH, NO$_x$, and CH$_4$, thus directly affecting radiative forcing and global climate. However, the effect of the number of water molecules on the mechanisms for this new group of S$_N$2-type reactions of nitrogen oxides and the competition of these processes with hydrolysis have not yet been characterized. Here we present the mechanisms and timescales of S$_N$2-type substitution and hydrolysis reactions of N$_2$O$_5$ with seawater in the cluster series N$_2$O$_5$ + Cl$^-$ + nH$_2$O (n=1-5). Previous studies of the cluster N$_2$O$_5$ + Cl$^-$ + H$_2$O provide deep insights into the local behavior of these systems.$^c$ The presented studies of this cluster with water molecules added one-by-one allows for a detailed understanding of the effects of a solvation shell as it is built, providing a connection between the behavior of these small clusters and atmospherically relevant systems. Vibrational spectroscopic signatures of key intermediates are discussed and compared to recent and ongoing experiments.$^a$

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/104303

DOI

https://doi.org/10.15278/isms.2019.TH02

Copyright and License Information

Copyright 2019 Laura M. McCaslin

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