Project abstract for group leopoldk

Structure and Dynamics of Molecular Complexes

This group uses supercomputing resources for carrying out quantum chemical calculations on the structures and internal dynamics of weakly bound molecular complexes. Their most recent interests involve complexes of carboxylic acids with amines and sulfur-containing acids. These systems have relevance not only to a fundamental understanding of intermolecular interactions, but to better understanding the early processes that take place during the nucleation of atmospheric aerosol. Recent work has focused on the formic acid – trimethylamine complex ((CH3)3N-HCOOH) as a prototype for alkylammonium carboxylates, which are postulated to play a role in promoting nucleation in the atmosphere. Other work has involved the reaction between sulfur trioxide and formic acid to form the previously uncharacterized species “formic sulfuric anhydride” (O2S(OH)OCHO).  Future work will explore additional complexes of these types, as well as their complexes with water. The aim is to elucidate the effect of microsolvation on reactivity.  The researchers also plan to return to studying water complexes of alkali halides (e.g., KCl-H2O and NaBr-H2O), which are pertinent to understanding the atmospheric activity of sea salt aerosol. For all these systems, ab initio and DFT calculations are used to narrow spectral searches, aid in the assignment of spectra, and supplement the interpretation of experimental results. The combination of theory and experiment provide a more complete picture of the systems the group studies than can be obtained from either one alone. MSI support also provides the flexibility to address new questions as they arise.

 A Research Spotlight about this work appeared on the MSI website in October 2015.

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