Re-examining ammonia addition to the Criegee intermediate: converging to chemical accuracy.
Re-examining ammonia addition to the Criegee intermediate: converging to chemical accuracy.
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DOI：
10.1039/c7cp08582f
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发表时间：
2018-03
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影响因子：
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通讯作者：
Jonathon P. Misiewicz;Sarah N. Elliott;Kevin B. Moore;H. Schaefer
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文献类型：
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作者：
Jonathon P. Misiewicz;Sarah N. Elliott;Kevin B. Moore;H. Schaefer
稳定的克里吉中间体(SCI)是在不饱和碳氢化合物的臭氧分解过程中形成的，与羟基自由基和气溶胶的形成有关。前人的理论研究[S.Jórgenson和A.Gross，J.Phys.化学。2009年，113,10284-10290]计算了氨与简单SCI加成的速率常数，但报告了量子化学能量的广泛分布，这取决于所使用的基组。我们报道了这些反应在CCSD(T)/ANO2和CCSD(T)/ANO1水平上的优化几何构型，以及CCSD(T)/CBS能量微扰四重修正。我们发现四重微扰修正的加入使过渡态的能量相对于反应物提高了0.76-0.88千卡·摩尔~(-1)，从而定性地改变了反应面。我们计算了速率常数，发现约根森和格罗斯之前高估了氨加成到SCI的速率常数，但在一个数量级内。这支持了Vereecken等人之前的结论。访问数/每百万人：Reach for[L.Vereecken.化学。化学。PHYS，2012，14,14682-14695]向SCI中添加氨是Criegee中间体的一个可以忽略不计的汇。
Stabilized Criegee intermediates (SCI) are formed during the ozonolysis of unsaturated hydrocarbons and have been implicated in the formation of hydroxyl radicals and aerosols. Previous theoretical research [S. Jørgenson and A. Gross, J. Phys. Chem. A, 2009, 113, 10284-10290] computed the rate constants for addition of ammonia to simple SCIs, but reported a wide distribution of quantum chemical energies, depending on the basis set used. We report optimized geometries for these reactions at the CCSD(T)/ANO2 and CCSD(T)/ANO1 levels, and CCSD(T)/CBS energies with perturbative quadruples corrections. We find the inclusion of perturbative quadruples corrections elevates the energy of the transition state by 0.76-0.88 kcal mol-1 relative to the reactants, which qualitatively changes the reaction surface. We calculate rate constants and find that Jørgenson and Gross previously overestimated the rate constants for ammonia addition to SCIs, but were within an order of magnitude. This supports the previous conclusion of Vereecken et al. [L. Vereecken, H. Harder and A. Novelli, Phys. Chem. Chem. Phys., 2012, 14, 14682-14695] that ammonia addition to SCIs is a negligible sink of Criegee intermediates.