Structures, Hydration, and Electrical Mobilities of Bisulfate Ion-Sulfuric Acid-Ammonia/Dimethylamine Clusters: A Computational Study

Narcisse T. Tsona, Henning Henschel*, Nicolai Bork, Ville Haapasilta, Hanna Vehkamaki

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

26 Citations (Scopus)

Abstract

Despite the well-established role of small molecular clusters in the very first steps of atmospheric particle formation, their thermochemical data are still not completely available due to limitation of the experimental techniques to treat such small clusters. We have investigated the structures and the thermochemistry of stepwise hydration of clusters containing one bisulfate ion, sulfuric acid, base (ammonia or dimethylamine), and water molecules using quantum chemical methods. We found that water facilitates proton transfer from sulfuric acid or the bisulfate ion to the base or water molecules, and depending on the hydration level, the sulfate ion was formed in most of the base-containing clusters. The calculated hydration energies indicate that water binds more strongly to ammonia-containing clusters than to dimethylamine-containing and base-free clusters, which results in a wider hydrate distribution for ammonia-containing clusters. The electrical mobilities of all clusters were calculated using a particle dynamics model. The results indicate that the effect of humidity is negligible on the electrical mobilities of molecular clusters formed in the very first steps of atmospheric particle formation. The combination of the results of this study with those previously published on the hydration of neutral clusters by our group provides a comprehensive set of thermochemical data on neutral and negatively charged clusters containing sulfuric acid, ammonia, or dimethylamine.

Original languageEnglish
Pages (from-to)9670-9679
Number of pages10
JournalJournal of Physical Chemistry A
Volume119
Issue number37
DOIs
Publication statusPublished - 17 Sep 2015
MoE publication typeA1 Journal article-refereed

Keywords

  • GALACTIC COSMIC-RAYS
  • ATMOSPHERICALLY RELEVANT CLUSTERS
  • MOLECULAR CLUSTERS
  • AEROSOL NUCLEATION
  • PARTICLE FORMATION
  • BINDING-ENERGIES
  • AIR-POLLUTION
  • AMMONIA
  • GROWTH
  • AMINE

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