Date of Award
1-1-2025
Degree Type
Dissertation
Degree Name
Doctor of Philosophy in Chemistry
Department
Chemistry
First Advisor
Dugan Hayes
Abstract
Optical transient absorption spectroscopy is a fundamental pump-probe technique that is used to analyze the photophysical and photochemical properties of molecules. Our research group specifically utilizes both a femtosecond and nanosecond set up to probe dynamics of molecules on time scales ranging from 100s of femtoseconds to approximately 50 microseconds. Chapter 2 is a standard operating procedure for the nanosecond transient absorption instrument.
Photoacids are molecules that undergo a change in the acidity of one of their protons when exposed to light. Utilizing this phenomenon, we have designed a series of dyes that, when bound to divalent first row transition metals, can act as a photoinduced “switch”, opening the door for potential applications as a method to physically separate charge transfer states to control recombination pathways. Chapters 3 and 4 are a study on the photophysical dynamics of a coumarin derivative, 4-methylesculetin (4ME), that has been augmented with dipicolylamine (DPA) and then subsequently coordinated to divalent first row transition metals. Using a combination of X-ray and optical transient absorption spectroscopies, we have studied configuration dynamics on these complexes and report on their potential future uses as photoswitches.
The aqueous ferrate(VI) ion has been studied as a powerful green oxidant for micropollutants in wastewater. While much has been done to elucidate information on the mechanism of ferrate(VI) degradation, as well as its effects on pollutant oxidation, there are still limitations in terms of large-scale use. In order to gain a better understanding of the photoactivation of the aqueous ferrate(VI) ion, we used UV LED chips in an attempt to activate the LMCT state to observe degradation of common organic micropollutants. We also studied the use of visible light to facilitate two-photon absorption of the 3T1 states in an attempt to activate the higher energy LMCT state, which is discussed in Chapter 5.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Jacoby, Danielle, "DYNAMICS OF METAL-COORDINATED COUMARIN DYES FOR PHOTOSWTICHING APPLICATIONS" (2025). Open Access Dissertations. Paper 4455.
https://digitalcommons.uri.edu/oa_diss/4455