The Organic and Macromolecular Chemistry Program supports the studies of Professor Richard Weiss on the effects of structural and/or electronic anisotropy imposed by liquid crystals, polymers, and gels on guest molecules. Molecules with well-established spectral and photochemical properties in fluid solution will be incorporated into these media, and their reactivity in the different media compared to elucidate structural and electronic influences imposed by the media. Conversely, well defined anisotropic environments will be employed to impose specific influences on the guest thereby providing insights into the fundamental factors affecting specific transformations within these constrictive environments. Undergraduate and graduate students involved in this research will be exposed to a variety of photochemical, fast reaction and spectroscopic techniques, and their application to materials characterization. With this Renewal award, the Organic and Macromolecular Chemistry Program supports the research and educational activities of Professor Richard Weiss of Georgetown University. Professor Weiss will focus his research on elucidating the structural and electronic effects imposed by liquid crystals, polymers, and gels on the photochemical reactivity of incorporated molecules, called guests. The local microenvironment imposed by these materials influences the reactivity of the guest, and changes in the reactivity of the guest, when compared to that in fluid solution, offer unique insights into materials processing at the molecular level. The educational activities of Professor Weiss include the training of graduate and undergraduate students in spectroscopy, fast reaction techniques and materials characterization.