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Title: Transient absorption studies of biologically relevant systems : photostability and photoactivation
Author: Greenough, Simon E.
ISNI:       0000 0004 5357 653X
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 2014
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Two areas of study are presented in this thesis: photostability of biomolecules and photoactivation of transition metal complexes. The implementation of a newly constructed transient absorption spectrometer, to investigate relevant photodissociation reactions in solution, is documented and includes a description of a gravity driven thin-film liquid jet, which may prove useful to spectroscopists seeking to remove sample/glass interaction or maximise their temporal resolution. Toward the subject of photostability of biomolecules, solvent induced conformer-specific photodissociation dynamics of guaiacol are elucidated. A particular photodissociation channel is observed to effectively be switched on or off depending on the solvent (cyclohexane or methanol) used. This is attributed to the interchangeable solvent specific conformers of guaiacol; an intramolecular H-bond between OH and OMe moieties is formed in cyclohexane whereas an intermolecular H-bond between OH and solvent is formed in methanol. The latter is thought to lower a barrier to O–H dissociation and facilitates H-atom loss via tunnelling. The photoactivation mechanism of cis-[Ru(bipyridine)2(nicotinamide)2]2+, a photoactive species designed to display high cytotoxicity following irradiation, for potential use in photodynamic therapy (photochemotherapy), is investigated. The photoactivation process is shown to occur with a high quantum yield and on an ultrafast timescale. Importantly, the conclusions here provide a detailed understanding of the initial stages involved in this photoactivation and the foundation required for designing more efficacious photochemotherapy drugs of this type.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: QD Chemistry