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Title: Deprotonated Dicarboxylic Acid Homodimers: Hydrogen Bonds and Atmospheric Implications

Dicarboxylic acids represent an important class of water-soluble organic compounds found in the atmosphere. In this work we are studying properties of dicarboxylic acid homodimer complexes (HO2(CH2)nCO2-[HO2(CH2)nCO2H], n = 0-12), as potentially important intermediates in aerosol formation processes. Our approach is based on experimental data from negative ion photoelectron spectra of the dimer complexes combined with updated measurements of the corresponding monomer species. These results are analyzed with quantum-mechanical calculations, which provide further information about equilibrium structures, thermochemical parameters associated with the complex formation, and evaporation rates. We find that upon formation of the dimer complexes the electron binding energies increase by 1.3–1.7 eV (30.0–39.2 kcal/mol), indicating increased stability of the dimerized complexes. Calculations indicate that these dimer complexes are characterized by the presence of strong intermolecular hydrogen bonds with high binding energies and are thermodynamically favorable to form with low evaporation rates. Comparison with previously studied HSO4-[HO2(CH2)2CO2H] complex (J. Phys. Chem. Lett. 2013, 4, 779-785) shows that HO2(CH2)2CO2-[HO2(CH2)2CO2H] has very similar thermochemical properties. These results imply that dicarboxylic acids not only can contribute to the heterogeneous complexes formation involving sulfuric acid and dicarboxylic acids, but also can promote the formation of homogenous complexes by involving dicarboxylic acids themselves.
Authors:
; ;
Publication Date:
OSTI Identifier:
1327107
Report Number(s):
PNNL-SA--115831
Journal ID: ISSN 1089-5639; 48537; KC0301050; KP1704020
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory; Journal Volume: 120; Journal Issue: 15
Publisher:
American Chemical Society
Research Org:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL); Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 54 ENVIRONMENTAL SCIENCES Environmental Molecular Sciences Laboratory