| The role of environment on photoinduced electron transfer is examined in a series of donor-acceptor molecules. In the first part of the dissertation, the influence of the solvent environment on aminonaphthalimides is examined. The solvent influences electron transfer through energetic effects as well as through modulation of the molecular motion of the donor-acceptor systems. In these systems, rotation of the amino group is found to gate electron transfer. In a second series of aminonaphthalimides, the nature of the amino group was varied. Three aromatic systems of various sizes were placed as secondary donors off the 4-amino position. As the size of the aromatic system increases more positive charge is localized in the secondary donor.; In the second part of the dissertation, the photophysics of self-assembled stacked aromatic arrays is explored. In these systems the environment is another array of the aromatic molecules, not solvent. The neighboring arrays influence the energetics of the system through exciton coupling. In several cases, despite the changes in energetics, the dynamics of photoinduced electron transfer do not change. In a few systems, new electron transfer pathways are created when the system is assembled. These pathways are not available in the disaggregated state, and no electron transfer occurs.; This dissertation also explores energy migration through self-assembled stacked aromatic arrays, and finds that singlet-singlet annihilation is a common deactivation pathway for most assemblies. Additionally, energy-hopping rates are determined for the structurally well-characterized aggregates, and are found to be on the order of picoseconds within an array and are subpicosecond between the arrays. There is also an attempt to use the annihilation time constant to estimate aggregate size, thus allowing the photophysics to provide structural information. |
