Structural dynamics of PAH
molecules upon energetic photon or
ion interactions
Geert Reitsma
Zernike Institute PhD thesis number:
ISSN:
ISBN (printed version):
ISBN (electronic version):
2014-19
570-1530
978-90-367-7333-1
978-90-367-7332-4
Cover:
The molecule model was generated by GaussView and the photograph was
taken at BESSY II, Berlin.
Printed by:
Ipskamp Drukkers, Enschede, November 2014
The research presented in this PhD thesis was performed in the research group Quantum
Interactions and Structural Dynamics (QISD). Up to 31-12-2013 this group was embedded in
the Kernfysisch Versneller Institute (KVI) under the name Atomic and Molecular Physics.
From 01-01-2014 the group is part of the Zernike Institute for Advanced Materials at the
University of Groningen, The Netherlands.
The work was funded by the NWO Dutch Astrochemistry Network. It received additional
funding from the COST action CM0805. The beamtimes were allocated by the Helmholtz
Zentrum Berlin and financially supported by the European Community’s Seventh Framework
Programme.
Structural dynamics of PAH
molecules upon energetic photon or
ion interactions
Proefschrift
ter verkrijging van de graad van doctor aan de
Rijksuniversiteit Groningen
op gezag van de
rector magnificus prof. dr. E. Sterken
en volgens besluit van het College voor Promoties.
De openbare verdediging zal plaatsvinden op
maandag 1 december 2014 om 12.45 uur
door
Geert Reitsma
geboren op 24 maart 1986
te Dongeradeel
Promotor
Prof. dr. ir. R.A. Hoekstra
Copromotor
Dr. T.A. Schlathölter
Beoordelingscommissie
Prof. dr. A.G.G.M. Tielens
Prof. dr. P. Rudolf
Prof. dr. H. Cederquist
ISBN (gedrukte versie)
:
978-90-367-7333-1
ISBN (elektronische versie) :
978-90-367-7332-4
Contents
1 Introduction
1.1 Identification and characterization of PAHs in
1.2 Ion processing of PAHs . . . . . . . . . . . .
1.2.1 Excitation energy . . . . . . . . . . . .
1.2.2 Dissociation dynamics . . . . . . . . .
1.3 Hydrogenation of PAHs . . . . . . . . . . . .
1.4 X-ray absorption of PAHs . . . . . . . . . . .
1.5 Quantum chemical calculations . . . . . . . .
1.5.1 Interpretation of the experiments . . .
1.6 Summary of the contents of this thesis . . . .
the ISM
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2 Activation energies for fragmentation channels of anthracene
cations - experiment and theory
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Experimental and computational approach . . . . . . . . . . . . .
2.3 Results and discussion . . . . . . . . . . . . . . . . . . . . . . . .
2.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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3 Ion-PAH collisions: kinetic energy releases for specific fragmentation channels
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Experimental approach . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.1 Time-of-flight mass spectra and correlation diagrams . . . . .
3.4.2 Kinetic energy releases . . . . . . . . . . . . . . . . . . . . . .
3.4.3 Reverse barrier calculations . . . . . . . . . . . . . . . . . . .
3.4.4 Astrophysical context . . . . . . . . . . . . . . . . . . . . . .
3.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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4 De-excitation dynamics of superhydrogenated PAH cations after
soft X-ray absorption
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4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4.2 Experimental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
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4.3
4.4
Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5 Near edge X-ray absorption mass spectrometry on coronene
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2 Experimental method . . . . . . . . . . . . . . . . . . . . . . . .
5.3 Results and discussion . . . . . . . . . . . . . . . . . . . . . . . .
5.3.1 General features of the mass spectra . . . . . . . . . . . .
5.3.2 NEXAMS spectra . . . . . . . . . . . . . . . . . . . . . .
5.3.3 Dehydrogenation and fragmentation dynamics . . . . . .
5.3.4 Evaporation model . . . . . . . . . . . . . . . . . . . . . .
5.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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6 Femtosecond laser induced ionization and dissociation of gas-phase
protonated leucine enkephalin
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6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
6.2 Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.2.1 Mass spectrometer . . . . . . . . . . . . . . . . . . . . . . . . 91
6.2.2 Laser system . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.3 Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.3.1 Mass spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.3.2 Partial ion yields . . . . . . . . . . . . . . . . . . . . . . . . . 98
6.3.3 Pump-probe spectroscopy . . . . . . . . . . . . . . . . . . . . 99
6.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
6.5 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
6.6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
7 Summary
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Nederlandse samenvatting
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Dankwoord
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Co-authored publications
119