Experimental and theoretical investigations of the photochemistry of styrene and the creation and characterisation of shaped femtosecond ultraviolet laser pulses.
Doctoral thesis, UCL (University College London).
This thesis is composed of three projects that are linked by the theme of light-molecule interactions. These are covered separately in Chapters 2, 3, and 4. In Chapter 1 some background to the thesis is described so that the various links between the science in the different chapters, and the motivation for the project as a whole are explained. Elements of photochemistry, both experimental and theoretical, are described in this chapter and some material about the most important experimental tools used in this work, ultrafast lasers, is covered, as well as the methodology of time-resolved spectroscopies, and timeresolved photoelectron spectroscopy in particular; the field of laser control of chemistry is also briefly reviewed. Chapter 2 is an account of the design and use of a UV pulse shaper and characterisation setup. This is an applied optics experiment, whose application is to the control of photochemical reactions with specifically shaped ultrafast laser light. Several demonstrations of the pulse shaping capacity of this new experiment are presented. In Chapter 3, calculation of the excited electronic states of the molecule styrene is described. This project is a computational study of the electronic spectroscopy and ionisation of the styrene molecule. In Chapter 4, the direct observation of internal conversion in styrene using time-resolved photoelectron spectroscopy is reported. This is an experimental laser spectroscopy project in which some of the results from the computations in the theory project, Chapter 3, will be used to analyse the experimental spectra. Chapter 5 summarises the conclusions drawn from Chapters 2, 3 and 4 and provides an outlook for future research based on the work in this thesis. Throughout this thesis, but more particularly in Chapters 1 and 2, there is quite a large volume of literature review and background material. This content reflects the personal perspective from which the thesis was approached. Much of the field of ultrafast optics and spectroscopy was entirely new to the writer at the outset of the PhD programme, and most of the review-based writing about these topics found here was originally written early on in the PhD project, as a means of helping to bridge the gap between work on optical experiment design and an undergraduate training in chemistry.
|Title:||Experimental and theoretical investigations of the photochemistry of styrene and the creation and characterisation of shaped femtosecond ultraviolet laser pulses|
|Open access status:||An open access version is available from UCL Discovery|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Chemistry|
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