Investigation of the behavior of tropospheric relevant compounds at the interface gas/organic acid aerosols: An ONIOM QM/MM study
Authors: Roose Antoine , Duflot Denis , Fotsing Kwetche Césaire , Toubin Céline 
Published: March 2021

&lt;p&gt;The uptake of atmospheric gaseous oxidant such as O&lt;sub&gt;3&lt;/sub&gt; or the ROx (OH, HO&lt;sub&gt;2&lt;/sub&gt;, RO&lt;sub&gt;2&lt;/sub&gt;) family, have a strong impact on the oxidative capacity of the atmosphere. [1], [2] Last decade, few studies have been carried out on the uptake of such compounds on atmospheric aerosol. However, the large variety of organic compounds provides uptake coefficients with a wide range of order of magnitude. [3], [4] Furthermore, the uptake resulting from the combination of different processes (mass accommodation, bulk diffusion, reactivity), the detailed understanding of such a process is not always accessible through experiments. Theoretical tools such as quantum mechanics (QM) combined with Molecular Mechanics (MM) is one way to investigate separately the different processes.&lt;/p&gt;&lt;p&gt;The ONIOM hybrid QM/MM method [5] allows to study the reactivity of few molecules in a large system. In our group, a methodology using this computational method have been developed in order to estimate the reactive uptake of gaseous compounds onto organic aerosol particles. In this presentation, reactive uptake of HO&lt;sub&gt;2&lt;/sub&gt; and O&lt;sub&gt;3&lt;/sub&gt; onto glutaric acid and oleic acid aerosols respectively will be discussed. Comparisons will be addressed with gas phase theoretical reaction rates and with experimental data.&lt;/p&gt;&lt;p&gt;&lt;em&gt;We acknowledge support by the French government through the Program &amp;#8220;Investissement d'avenir&amp;#8221; through the Labex CaPPA (contract ANR-11-LABX-0005-01) and I-SITE ULNE project OVERSEE (contract ANR-16-IDEX-0004), CPER CLIMIBIO (European Regional Development Fund, Hauts de France council, French Ministry of Higher Education and Research) and French national supercomputing facilities (grants DARI x2016081859 and A0050801859).&lt;/em&gt;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References&lt;/p&gt;&lt;p&gt;[1]&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; H. L. Macintyre and M. J. Evans, &amp;#8220;Parameterisation and impact of aerosol uptake of HO2 on a global tropospheric model,&amp;#8221; Atmos. Chem. Phys., vol. 11, no. 21, pp. 10965&amp;#8211;10974, Nov. 2011, doi: 10.5194/acp-11-10965-2011.&lt;/p&gt;&lt;p&gt;[2]&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; M. Zeng and K. R. Wilson, &amp;#8220;Efficient Coupling of Reaction Pathways of Criegee Intermediates and Free Radicals in the Heterogeneous Ozonolysis of Alkenes,&amp;#8221; The Journal of Physical Chemistry Letters, Jul. 2020, doi: 10.1021/acs.jpclett.0c01823.&lt;/p&gt;&lt;p&gt;[3]&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; P. S. J. Lakey, I. J. George, L. K. Whalley, M. T. Baeza-Romero, and D. E. Heard, &amp;#8220;Measurements of the HO2 Uptake Coefficients onto Single Component Organic Aerosols,&amp;#8221; Environ. Sci. Technol., vol. 49, no. 8, pp. 4878&amp;#8211;4885, Apr. 2015, doi: 10.1021/acs.est.5b00948.&lt;/p&gt;&lt;p&gt;[4]&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; M. Mendez, N. Visez, S. Gosselin, V. Crenn, V. Riffault, and D. Petitprez, &amp;#8220;Reactive and Nonreactive Ozone Uptake during Aging of Oleic Acid Particles,&amp;#8221; J. Phys. Chem. A, vol. 118, no. 40, pp. 9471&amp;#8211;9481, Oct. 2014, doi: 10.1021/jp503572c.&lt;/p&gt;&lt;p&gt;[5]&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; L. W. Chung et al., &amp;#8220;The ONIOM Method and Its Applications,&amp;#8221; Chem. Rev., vol. 115, no. 12, pp. 5678&amp;#8211;5796, Jun. 2015, doi: 10.1021/cr5004419.&lt;/p&gt;