Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University , P.O. Box 5825, Doha, Qatar.
J Am Chem Soc. 2017 Jan 11;139(1):27-30. doi: 10.1021/jacs.6b10208. Epub 2016 Nov 16.
Interfacial chemistry involving glyoxal at aerosol surfaces is postulated to catalyze aerosol growth. This chemistry remains speculative due to a lack of detailed information concerning the physicochemical behavior of glyoxal at the interface of atmospheric aerosols. Here, we report results from high-level electronic structure calculations as well as both classical and Born-Oppenheimer ab initio molecular dynamics simulations of glyoxal solvation at the air/liquid water interface. When compared to the gas phase, the trans to cis isomerization of glyoxal at the liquid water interface is found to be catalyzed; additionally, the trans conformation is selectively solvated within the bulk to a greater degree than is the cis conformation. These two processes, i.e., the catalytic effect at the water interface and the differentially selective solvation, act to enhance the concentration of the cis isomer of glyoxal at the water interface. This has important consequences for the interpretation of experiments and for the modeling of glyoxal chemistry both at the interface of water clouds and at aerosols. Broader implications of this work relate to describing the role of interfaces in selecting specific stereo molecular structures at interfacial environments.
界面化学涉及到气溶胶质子表面的乙二醛，被认为可以催化气溶胶的生长。由于缺乏有关大气气溶胶界面上乙二醛物理化学行为的详细信息，这种化学仍然是推测性的。在这里，我们报告了高水平电子结构计算的结果，以及在空气/液态水界面上乙二醛溶剂化的经典和 Born-Oppenheimer 从头分子动力学模拟的结果。与气相相比，在液态水界面上，乙二醛的反式到顺式异构化被发现是催化的；此外，顺式构象在本体中比反式构象更有选择性地溶剂化。这两个过程，即在水界面的催化作用和不同的选择性溶剂化，作用是增加水界面上顺式乙二醛异构体的浓度。这对解释实验和模拟水云和气溶胶界面上乙二醛化学都有重要的影响。这项工作的更广泛的意义涉及到描述界面在选择界面环境中特定立体分子结构方面的作用。
