|
Titel |
Amine substitution into sulfuric acid – ammonia clusters |
VerfasserIn |
O. Kupiainen, I. K. Ortega, T. Kurtén, H. Vehkamäki |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1680-7316
|
Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 8 ; Nr. 12, no. 8 (2012-04-16), S.3591-3599 |
Datensatznummer |
250011062
|
Publikation (Nr.) |
copernicus.org/acp-12-3591-2012.pdf |
|
|
|
Zusammenfassung |
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. |
|
|
Teil von |
|
|
|
|
|
|