UC Berkeley

The research presented in this dissertation focuses on understanding the regulation of excited states, both in natural photosynthesis and in artificial systems.

Chapters 1, 2, and 3 contribute to the understanding of natural photosynthesis by describ- ing a mathematical model that quantifies a process by which plants protect themselves from damage due to excess absorbed energy. Chapter 1 contains a description of a mathematical model of photosynthetic processes that govern the rapid components of nonphotochemical quenching. Chapter 2 contains a manual describing a Graphical User Interface (GUI) for this model. Chapter 3 extends the model of nonphotochemical quenching and applies the model to understand the role of the specific pigments and proteins which are required for rapidly-reversible nonphotochemical quenching to take place.

Chapters 4 and 5 are focused on experimental work done on artificial systems. Chapter 4 reports on the excited state dynamics of a pH-sensitive dye that has been used to regulated the excited state lifetime of an artificial antenna. Chapter 5 reports measurements of four molecular donor-bridge-acceptor triads where the bridge between the donor and acceptor is different in each triad, with the aim of understanding how the chemical bonding between donor and acceptor affects the timescales and yield of energy transfer and charge separation.