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Über dieses Buch

Jonelle Harvey's book outlines two related experimental techniques, threshold photoelectron spectroscopy and threshold photoelectron photoion coincidence techniques, which are utilised to investigate small halogenated molecules. All the experiments were conducted at the vacuum ultraviolet beamline of the Swiss Light Source, a synchrotron photon source, which has the advantage over popular laser photon-sources of extreme ease of tunability. Three studies are presented which combine experimental and computational ab initio approaches: studying the fast dissociations of halogenated methanes in order to construct a self-consistent thermochemical network; investigating the fragmentations of fluoroethenes from timebombs, which break apart very slowly but explosively, to fast dissociators; and uncovering how vital conical interactions underpin both the results of photoelectron spectra and dissociation patterns. The details included in this thesis are useful for researchers working in the same field and those readers wishing to obtain a solid introduction into the types of systems encountered in threshold photoelectron photoion coincidence spectroscopy.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction and Background Information

Abstract
This thesis is divided into seven chapters, the introduction, experimental, theory, three results chapters, conclusion and further work. The results of this thesis are presented in three parts: (i) Chap. 4, the study of fast dissociative photoionization reactions of selected halogenated methane cations, (ii) Chap. 5, the study of the fast and slow dissociative photoionization reactions of larger fluorinated ethene cations and (iii) Chap.​ 6, the study of the fates of the ground and excited electronic states of fluorinated ethene cations. Two themes are prevalent throughout the work, (a) the unimolecular dissociation dynamics of the photoionized molecules and what thermochemical values may be determined from them, and (b) the photoionization of neutral molecules probing the potential energy surfaces and discovering what can be gleaned from investigating the excited states. A summary of the results is presented in the conclusions and further work, in which new directions this work can take are discussed.
Jonelle Harvey

Chapter 2. Experimental

Abstract
This chapter concerns the experimental facet of the work undertaken during this PhD. It begins by describing the light source used to ionize the molecules, followed by how that light is manipulated and a description of the endstation with which the experiments are performed. It concludes by detailing how the electron and ion signals are detected, and finally how the data is prepared for analysis.
Jonelle Harvey

Chapter 3. Theory

Abstract
This chapter is about the computational approaches used in the analysis of the experimental data. Computational methods have been used within the work presented in this thesis in combination with the experimental results, to help untangle the dissociation dynamics, determine thermochemical values and provide a more complete picture of the potential energy surfaces.
Jonelle Harvey

Chapter 4. Fast Dissociations of Halogenated Methanes: A Thermochemical Network

Abstract
The work presented in this chapter has been published as a journal article entitled ‘A Halomethane Thermochemical Network from iPEPICO Experiments and Quantum Chemical Calculations’ in 2012 by J. Harvey, R. P. Tuckett and A. Bodi, in the Journal of Physical Chemistry A, volume 116, issue 39, pages 9696-9705. The majority of the data collection and analysis was performed by the author, however, the assistance lent by Ms Nicola Rogers, Drs Mathew Simpson Andras Bodi, Melanie Johnson and Professor Richard Tuckett during beamtime with the collection of the data is gratefully acknowledged. The modelling program was developed by Sztáray [1]. The threshold photoelectron spectra can be found in Appendix C.
Jonelle Harvey

Chapter 5. Photodissociation Dynamics of Four Fluorinated Ethenes: Fast, Slow, Statistical and Non-statistical Reactions

Abstract
The results presented in this chapter have been previously published as a journal article entitled ‘Dissociation dynamics of fluorinated ethene cations: from time bombs on a molecular level to double-regime dissociators’ by J. Harvey, A. Bodi, R. P. Tuckett and B. Sztáray, in 2012 in the Royal Society of Chemistry journal, Physical Chemistry Chemical Physics, volume 14, pages 3935–3948.
Jonelle Harvey

Chapter 6. Threshold Photoelectron Spectra of Four Fluorinated Ethenes from the Ground Electronic State to Higher Electronic States

Abstract
The work presented in this chapter has been accepted for publication as a journal article entitled ‘Vibrational and electronic excitations in fluorinated ethene cations from the ground up’ in 2013 by J. Harvey, P. Hemberger, A. Bodi and R. P. Tuckett, in the Journal of Chemical Physics. 2013, issue 138, pages 124301–124313. The majority of the data collection and analysis was performed by myself; however, the assistance lent by Ms Nicola Rogers, Drs Matthew Simpson, Andras Bodi, Melanie Johnson, and Professor Richard Tuckett during beamtime with the collection of the data, and Dr Patrick Hemberger with data analysis is gratefully acknowledged. I particularly wish to thank Dr Andras Bodi for his assistance and useful discussions relating to the excited dynamics Sect. 6.2.3. The modelling program used to model the threshold photoelectron spectra was developed by Spangenberg et al. [1].
Jonelle Harvey

Chapter 7. Conclusions and Further Work

Abstract
The different aspects of the imaging photoelectron photoion coincidence apparatus have been utilized to investigate the fast and slow dissociation dynamics of small halogenated cations, and to explore their potential energy surfaces in the ground and excited electronic states.
Jonelle Harvey

Backmatter

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