| This dissertation describes the development and application of two-color three pulse photon echo peak shift spectroscopy (2C3PEPS).;Chapter 1 gives the motivation for developing 2C3PEPS. It details some of the physical and chemical processes where new information and deeper understanding can be gained using 2C3PEPS. One of these is solvation. Others include some of the key underlying processes of photosynthesis, such as electronic coupling, energy transfer, and electron transfer. Gaining a better understanding of photosynthetic systems is a major aim of the research in this dissertation. Chapter 1 also briefly introduces theoretical and experimental aspects of 2C3PEPS.;Chapter 2 describes the application of 2C3PEPS to a study of solvation. Using Nile blue in acetonitrile and ethylene glycol as a model, this chapter shows how 2C3PEPS reveals which spectral regions are related to each other at different times. By choosing a series of color pairs spanning the absorption and fluorescence spectra of Nile blue, we are able to gain a better understanding of the physical mechanisms of solvation by analyzing these correlations.;Chapter 3 describes the ability of 2C3PEPS to accurately determine electronic mixing between molecules in a dimer. Measurements were carried out on a model system, the sandwich dimer lutetium bisphthalocyanine. 2C3PEPS is sensitive to the degree of correlation in the fluctuations of two mixed states, which corresponds to the degree of mixing.;Chapter 4 again describes the use of 2C3PEPS to determine electronic mixing, this time in the reaction center of purple photosynthetic bacteria. To determine the mixing between the B and H chromophores in the reaction center, an extension of theoretical work used in Chapter 3 is needed to incorporate the fast energy and electron transfer that takes place in the reaction center. This chapter shows the promise 2C3PEPS holds for yielding new information about complex systems. |
