Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Quantum Chemical Calculations on ESR, Core Excitations, and Isotope Effects in Molecular Systems
Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry.
2004 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In this thesis, quantum chemical calculations are undertaken mostly in order to interpret experimental results, but also to learn about computational techniques, their performance and their limitations. In paper I, the ionization-cleavage process of alkenes is investigated and two pathways are followed, one of initial cleavage and subsequent ionization and on the opposite, the other one of initial ionization and subsequent cleavage. The calculations reveal that ionization is best described by a vertical process, which is much faster than the relaxation of the molecule to its ionized structural minimum. Further, in paper II, the core hole excited state of ammonia is investigated and found to dissociate in an ultra-fast manner nicely explained by the calculated potential energy surface showing a very low barrier for dissociation. In paper III, the static and dynamic structures of two halogenated dimethyl ether radical cations are studied in ESR experiments, and it is found that, while the chlorinated molecule remains unaffected, the fluorinated molecule undergoes a dissociation or association reaction before the measurement takes place, the resulting fragments are searched for but not identified decisively. In paper IV, the stability of Jahn-Teller distorted selectively deuteriated benzene radical cation isotopomers is investigated by ESR experiments and density functional theory calculations. The temperature dependence, between 4.2 K and 77 K, of the ESR spectra is explained. Finally, in paper V, the hydrogen inversion in aziridine and methyl and dimethyl substituted aziridines is investigated. The rate constants and kinetic isotope effects are calculated using various techniques of transition state theory and tunneling correction methods.

Place, publisher, year, edition, pages
2004. , p. 42
Series
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-232X ; 966
Keywords [en]
Quantum chemistry
Keywords [sv]
Kvantkemi
National Category
Theoretical Chemistry
Identifiers
URN: urn:nbn:se:uu:diva-4226ISBN: 91-554-5943-9 (print)OAI: oai:DiVA.org:uu-4226DiVA, id: diva2:164453
Public defence
2004-05-07, Polhemsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 13:15
Opponent
Supervisors
Available from: 2004-04-15 Created: 2004-04-15Bibliographically approved
List of papers
1. Cleavage of Neutral Alkenes and Alkene Radical Cations: Hybrid Hartree-Fock/Density Functional Theory Results
Open this publication in new window or tab >>Cleavage of Neutral Alkenes and Alkene Radical Cations: Hybrid Hartree-Fock/Density Functional Theory Results
1998 In: Canadian Journal of Chemistry, ISSN 0008-4042, Vol. 76, p. 1817-1826Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-91647 (URN)
Available from: 2004-04-15 Created: 2004-04-15Bibliographically approved
2. Evidence of Ultra-Fast Dissociation in Ammonia Observed by Resonant Auger Electron Spectroscopy
Open this publication in new window or tab >>Evidence of Ultra-Fast Dissociation in Ammonia Observed by Resonant Auger Electron Spectroscopy
Show others...
2003 In: Chemical Physics Letters, ISSN 0009-2614, Vol. 370, p. 781-788Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-91648 (URN)
Available from: 2004-04-15 Created: 2004-04-15Bibliographically approved
3. Static and Dynamic Structure of Halogenated Dimethyl Ether Radical Cation: An EPR and MO Study
Open this publication in new window or tab >>Static and Dynamic Structure of Halogenated Dimethyl Ether Radical Cation: An EPR and MO Study
Show others...
2002 In: Physical Chemistry Chemical Physics, ISSN 1463-9076, Vol. 4, no 12, p. 2524-2529Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-91649 (URN)
Available from: 2004-04-15 Created: 2004-04-15Bibliographically approved
4. Isotope Effects on the Jahn-Teller Distortion of Partially Deuteriated Benzene Cation Radicals: An Experimental and Theoretical Density Functional Theory Study
Open this publication in new window or tab >>Isotope Effects on the Jahn-Teller Distortion of Partially Deuteriated Benzene Cation Radicals: An Experimental and Theoretical Density Functional Theory Study
Show others...
2004 In: Physical Chemistry Chemical Physics, ISSN 1463-9076, Vol. 6Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-91650 (URN)
Available from: 2004-04-15 Created: 2004-04-15Bibliographically approved
5. Theoretical Calculations of Kinetic Isotope Effects for a Series of Aziridines
Open this publication in new window or tab >>Theoretical Calculations of Kinetic Isotope Effects for a Series of Aziridines
Show others...
2004 (English)In: Fundamental World of Quantum Chemistry: A Tribute to the Memory of Per-Olov Löwdin, Volume 3 / [ed] Brändas, Erkki J. and Kryachko, Eugene S., Dordrecht: Kluwer Academic Publishers , 2004Chapter in book (Refereed)
Abstract [en]

The nitrogen inversion in aziridine and som parent substituted aziridines is investigated using various computational methods. The stationary points on each potential energy surface are optimized using the B3LYP functional of density functional theory (DFT) in conjuction with the popular 6-31G(d) basis set. Rate constants and thereby kinetic isotope effects (KIEs) are computed at different temperatures using transiton state theory (TST) and various techniques of variational transition state theory (VTST). Moreover, corrections are made for tunneling and non-classical reflection, using three semiclassic correction methods: the Wigner tunneling correction as well as the zero-curvature and the samll-curvature corrections. The performance of the various methods to compute KIEs are compared and the effects of tunneling are discussed.

Place, publisher, year, edition, pages
Dordrecht: Kluwer Academic Publishers, 2004
Keywords
Aziridnie, nitrogen inversion, kinetic isotope, effect, density functional theory calculations, variational transition state theory, Wigner-tunneling correction, zero-curvature tunneling correction, small-curvature tunneling correction
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-91651 (URN)978-1-4020-2583-9 (ISBN)978-90-481-6687-9 (ISBN)
Available from: 2004-04-15 Created: 2004-04-15 Last updated: 2011-04-09Bibliographically approved

Open Access in DiVA

fulltext(418 kB)1659 downloads
File information
File name FULLTEXT01.pdfFile size 418 kBChecksum MD5
a049c773cb8f5a0333c2b7ed535c2a5648204e38267a94d8eafdf37986dfb429fe6d19f3
Type fulltextMimetype application/pdf
Buy this publication >>

By organisation
Department of Quantum Chemistry
Theoretical Chemistry

Search outside of DiVA

GoogleGoogle Scholar
Total: 1659 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1086 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf