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<front>
<journal-meta>
<journal-id journal-id-type="publisher">ACP</journal-id>
<journal-title-group>
<journal-title>Atmospheric Chemistry and Physics</journal-title>
<abbrev-journal-title abbrev-type="publisher">ACP</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1680-7324</issn>
<publisher><publisher-name>Copernicus GmbH</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/acp-12-3591-2012</article-id>
<title-group>
<article-title>Amine substitution into sulfuric acid &amp;ndash; ammonia clusters</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kupiainen</surname>
<given-names>O.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ortega</surname>
<given-names>I. K.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kurtén</surname>
<given-names>T.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Vehkamäki</surname>
<given-names>H.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Division of Atmospheric Sciences, Department of Physics, P.O. Box 64, 00014 University of Helsinki, Finland</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Laboratory of Physical Chemistry, Department of Chemistry, P.O. Box 55, 00014 University of Helsinki, Finland</addr-line>
</aff>
<pub-date pub-type="epub">
<day>16</day>
<month>04</month>
<year>2012</year>
</pub-date>
<volume>12</volume>
<issue>8</issue>
<fpage>3591</fpage>
<lpage>3599</lpage>
<permissions>
<license xlink:type="simple">
<license-p>This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.</license-p>
</license>
</permissions>
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<self-uri xlink:href="http://www.atmos-chem-phys.net/12/3591/2012/acp-12-3591-2012.pdf">The full text article is available as a PDF file from http://www.atmos-chem-phys.net/12/3591/2012/acp-12-3591-2012.pdf</self-uri>
<abstract>
<p>The substitution of ammonia by dimethylamine in sulfuric acid – ammonia –
dimethylamine clusters was studied using a collision and evaporation
dynamics model. Quantum chemical formation free energies were computed using
B3LYP/CBSB7 for geometries and frequencies and RI-CC2/aug-cc-pV(T+d)Z for
electronic energies. We first demonstrate the good performance of our method
by a comparison with an experimental study investigating base substitution in
positively charged clusters, and then continue by simulating base exchange in
neutral clusters, which cannot be measured directly. Collisions of a
dimethylamine molecule with an ammonia containing positively charged cluster
result in the instantaneous evaporation of an ammonia molecule, while the
dimethylamine molecule remains in the cluster. According to our simulations,
a similar base exchange can take place in neutral clusters, although the
overall process is more complicated. Neutral sulfuric acid – ammonia clusters
are significantly less stable than their positively charged counterparts,
resulting in a competition between cluster evaporation and base exchange.</p>
</abstract>
<counts><page-count count="9"/></counts>
</article-meta>
</front>
<body/>
<back>
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