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Abstract

This dissertation aims to provide new methods of interrogating the nature of electronicdynamics in chiral materials. The superiority of photosynthetic light harvesting over any man-made solar light harvesting devices motivates the study of how chirality affects light harvesting. A two-dimensional ultrafast chiral spectroscopy is designed and built. This new instrumentation has the capability to provide vital and unique insight into ‘handed’ electronic dynamics. The theory behind the cancellation of achiral background is described. Great care is taken in the engineering of this instrument to optimize a very small signal against a large background. A novel approach to two-dimensional electronic spectroscopy in the pump-probe geometry is described. The ability to combine the background-free nature of the BOXCARS geometry with the inherent phase stability of the pump-probe geometry and a temporally separated LO results in a ‘best of both worlds’ spectrometer. A new model for the extraction of energy transfer time constants from two-dimensional electronic spectra is described. This method is further extended to the interpretation of two- dimensional circular dichroism spectroscopy. The result is the ability to extract ’handed’ energy transfer time constants from a simple three level model. Lastly, several future direction projects are proposed. First, the study of chiral memory in chiral aggregates of achiral porphyrin monomers. Then, the study of chiral dynamics in quantum dots capped with chiral ligands in the hopes of elucidating more about the origin of the QD’s CD signal. Then, an experiment to confirm a theoretically surface specific 2DES technique is proposed. And finally, a novel mixed electronic-Raman experiment is proposed to track the effect of groundstate vibrations on the outcome of photochemical reactions.

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