uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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
A Study of Substituent Effects for Aliphatic CH3-X Compounds by Resonant Auger Spectroscopy
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science, Surface and Interface Science.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science, Surface and Interface Science.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science, Surface and Interface Science.
Show others and affiliations
2009 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 11, no 5, 826-833 p.Article in journal (Refereed) Published
Abstract [en]

In this study linear free energy relationships (LFER) are applied to the relaxation of core-excited states in aliphatic CH3X compounds. There are at least two valence orbitals involved in Auger decay following CCH31s →σ*C–X excitation, which may as well be localized on the substituents in this series. Therefore, the observed property cannot be strictly attached to the so-called reaction center. The behavior of substituent constants in the description of core-hole processes in aliphatic compounds is also checked on C1s ionization potentials for the extended series of substituted methanes. The role of the inductive effect for both resonant Auger kinetic energies (Ek) and C1s binding energies (Ecoreb) is very important. CCH31s →σ*C–X excitation energies do not show any significant correlations with inductive substituent constants. On the contrary, Taft’s inductive parameters alone give good correlations for Ek. A simple model with ‘Z + 1’ approximation is developed to describe Ek and explain the observed correlations:Ek = Ecoreb− (Ev(Z)b + Eea(Z+1)+),where Ebv(Z) is the valence ionization potential for CH3X and Eea(Z+1)+ is the electron affinity for [NH3X]+.

Place, publisher, year, edition, pages
2009. Vol. 11, no 5, 826-833 p.
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:uu:diva-97318DOI: 10.1039/b805912hISI: 000262649300009OAI: oai:DiVA.org:uu-97318DiVA: diva2:172197
Available from: 2008-05-15 Created: 2008-05-15 Last updated: 2011-02-23Bibliographically approved
In thesis
1. Structure and Dynamics of Core-Excited Species
Open this publication in new window or tab >>Structure and Dynamics of Core-Excited Species
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In this thesis we have performed core-electron spectroscopy studies of gas phase molecular systems starting with smaller diatomic, continuing with triatomic and extending our research to more complex polyatomic ones. We can subdivide the results presented here into two categories: the first one focusing on electronic fine structure and effect of the chemical bonds on molecular core-levels and the other one dealing with nuclear dynamics induced by creation of a core hole. In our research we have mostly used synchrotron radiation based techniques such as X-ray Photoelectron (XPS), X-ray Absorption (XAS), normal and Resonant Auger (AES and RAS, respectively) and Energy-Selected Auger Electron PhotoIon COincidence (ES-AEPICO) spectroscopies.

We have demonstrated that resonant Auger spectroscopy can be used to aid interpretation of the features observed in XAS for Rydberg structures in the case of Cl2 and C1s−1π*1 states of allene molecules. The combined use of high-resolution spectroscopy with ab initio calculations can help the interpretation of strongly overlapped spectral features and disentangle their complex profiles. This approach enabled us to determine the differences in the lifetimes for core-hole 2p sublevels of Cl2 which are caused by the presence of the chemical bond. We have shown that contribution in terms of the Mulliken population of valence molecular orbitals is a determining factor for resonant enhancement of different final states and fragmentation patterns reached after resonant Auger decays in N2O.

We have also performed a systematic study of the dependence of the C1s resonant Auger kinetic energies on the presence of different substituents in CH3X compounds. For the first time we have studied possible isomerization reaction induced by core excitation of acetylacetone. We could observe a new spectral feature in the resonant Auger decay spectra which we interpreted as a signature of core-excitation-induced keto-enol tautomerism.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2008. x, 68 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 442
Keyword
Physics, Synchrotron radiation, X-ray Photoelectron Spectroscopy (XPS), X-ray Absorption Spectroscopy (XAS), Resonant Auger Spectroscopy (RAS), Auger Electron Spectroscopy (AES), Energy-Selected Auger Electron PhotoIon COincidence (ES-AEPICO), core excitation, core ionization, linear free energy relationships (LFER), molecular-field splitting, substituent effects, nuclear dynamics, isomerization, Cl2, N2O, methane derivatives, allene, acetylacetone, Fysik
Identifiers
urn:nbn:se:uu:diva-8904 (URN)978-91-554-7223-8 (ISBN)
Public defence
2008-06-05, Polhemsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 10:15
Opponent
Supervisors
Available from: 2008-05-15 Created: 2008-05-15Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Surface and Interface Science
In the same journal
Physical Chemistry, Chemical Physics - PCCP
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 473 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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