Sheng Xia, Zhao Hailiang, Du Lin
College of Chemistry, Chemical and Environmental Engineering, Henan University of Technology, Lianhua Street 100, 450001 Zhengzhou, China.
College of Chemistry, Chemical and Environmental Engineering, Henan University of Technology, Lianhua Street 100, 450001 Zhengzhou, China; Environment Research Institute, Shandong University, Shanda South Road 27, 250100 Jinan, China.
Chemosphere. 2017 Nov;186:331-340. doi: 10.1016/j.chemosphere.2017.08.008. Epub 2017 Aug 4.
Theoretical calculations at the B3LYP-D3/aug-cc-pVTZ (aug-cc-pV(T+d)Z for sulfur) level were used to investigate the contribution of methyl hydrogen sulfate (MHS) to new particle formation with the common atmospheric aerosol nucleation precursors including water (HO), ammonia (NH), and dimethylamine (DMA). A typical characteristic feature of the MHS-containing complexes is the formation of six- or eight-membered ring structures via SOH⋯O (MHS donor), OH⋯O/N (HO donor) and NH⋯O/N (NH/DMA donor). The stability of the complexes was evaluated based on the calculated binding energies. The molecular interactions between three molecules are found to be more thermodynamically favorable than the complexes consisting two molecules. The red shifts of the SOH-stretching (MHS donor) vibrational transitions with respect to the isolated monomers are much larger than the red shifts of the OH (HO donor) and NH-stretching (NH/DMA donor) vibrational transitions. Topological analysis shows that the electron density and Laplacian at the bond critical points beyond the range of hydrogen bonding criteria for most of the complexes. This is due to the strong acid-base interaction between MHS and DMA or NH, thus leads to a proton transfer from MHS to DMA or NH. Remarkably, the atmospheric relevance of the MHS-containing complexes is much higher than HSO, which is evaluated by combining the calculated thermodynamic data and the concentrations of the reactant species. This study reveals the environmental fate of MHS could serve as nucleation centers in new particle formation.
在B3LYP-D3/aug-cc-pVTZ（硫采用aug-cc-pV(T+d)Z）水平下进行理论计算，以研究硫酸氢甲酯（MHS）与常见的大气气溶胶成核前体（包括水（HO）、氨（NH）和二甲胺（DMA））对新粒子形成的贡献。含MHS配合物的一个典型特征是通过SOH⋯O（MHS供体）、OH⋯O/N（HO供体）和NH⋯O/N（NH/DMA供体）形成六元或八元环结构。基于计算出的结合能评估配合物的稳定性。发现三个分子之间的分子相互作用在热力学上比由两个分子组成的配合物更有利。相对于孤立单体，SOH伸缩振动跃迁（MHS供体）的红移比OH（HO供体）和NH伸缩振动跃迁（NH/DMA供体）的红移大得多。拓扑分析表明，对于大多数配合物，键临界点处的电子密度和拉普拉斯算子超出了氢键标准范围。这是由于MHS与DMA或NH之间存在强酸碱相互作用，从而导致质子从MHS转移到DMA或NH。值得注意的是，通过结合计算出的热力学数据和反应物物种的浓度评估，含MHS配合物的大气相关性远高于HSO。这项研究揭示了MHS在环境中的归宿可能是新粒子形成中的成核中心。
