A density functional theory study of the molecular interactions between a series of amides and sulfuric acid
A density functional theory study of the molecular interactions between a series of amides and sulfuric acid
复制标题
一系列酰胺与硫酸分子相互作用的密度泛函理论研究
DOI：
10.1016/j.chemosphere.2018.08.152
复制
发表时间：
2019
期刊：
影响因子：
8.8
通讯作者：
Wang Wenxing
中科院分区：
文献类型：
--
作者：
Ma Xiaohui;Sun Yanhui;Huang Zixiao;Zhang Qingzhu;Wang Wenxing
酰胺是大气中一类含氮的有机污染物，可通过与硫酸的相互作用影响大气气溶胶的形成。本文利用密度泛函理论研究了硫酸与甲酰胺、甲甲酰胺、二甲基甲酰胺、乙酰胺、甲乙酰胺和二甲基乙酰胺的分子相互作用。在M06-2X/6-311++G（3df,3pd）水平下进行几何优化和Gibbs自由能计算。结果表明，在298.15 K和1 atm下，h2so4中添加酰胺类物质可能对大气新粒子的形成有促进作用。在新粒子形成初期，酰胺与硫酸的结合能力强于氨，弱于甲胺。值得注意的是，反式甲基乙酰胺可能具有与二甲胺相似的稳定硫酸的能力。在有水存在的情况下，酰胺对新粒子的形成只有微弱的促进作用。此外，我们可以从蒸发速率推断，甲酰胺和硫酸的小分子团簇可能比大分子团簇更有利于能量。
Amides, a class of nitrogen-containing organic pollutants in the atmosphere, may affect the formation of atmospheric aerosols by the interactions with sulfuric acid. Here, the molecular interactions of sulfuric acid with formamide, methylformamide, dimethylformamide, acetamide, methylacetamide and dimethylacetamide was investigated by density functional theory. Geometry optimization and Gibbs free energy calculation were carried out at M06-2X/6-311++G(3df,3pd) level. The results indicate that the addition of amides to H2SO4might have a promoting effect on atmospheric new particle formation at 298.15 K and 1 atm. In the initial stage of new particle formation, the binding capacity of amides and sulfuric acid is stronger than ammonia, but weaker than methylamine. It is worth noting that thetrans-methylacetamide could have similar capabilities of stabilizing sulfuric acid as dimethylamine. In the presence of water, amides are found to only have a weak enhancement capability on new particle formation. In addition, we can infer from evaporation rate that the small molecule clusters of formamide and sulfuric acid may be more energetically favorable than macromolecule clusters.