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Anne Myers Kelley Physical and Analytical Chemistry: Raman Spectroscopies |
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Professor of Chemistry School of Natural Sciences e-mail: amkelley@ucmerced.edu Tel: 209-228-4345 |
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Our group's research focuses on using the inelastic laser light scattering technique known as resonance Raman spectroscopy to study the molecular details of how materials interact with light. Analysis of resonance Raman spectra allows us to determine the specific atomic-level motions that occur in a molecule immediately after it absorbs light. This information is particularly relevant to photochemistry, and our group studies the detailed mechanisms of very fast photochemical reactions that are related to those involved in human vision, plant photosynthesis, photography and xerography. A related area of interest is in materials that have strong nonlinear optical responses. Nonlinear optical materials are used in electro-optic modulators in telecommunications to convert electrical voice and data signals to optical signals for transmission down fiber-optic cables, as well as for advanced optical microscopy methods in biological and other imaging applications. We are using spectroscopic methods to understand and predict the nonlinear optical properties of molecules and, in particular, the manner in which those properties are modified by the intermolecular interactions that are necessarily present in useful materials. In parallel with our experimental work are continuing efforts to improve our methods for analyzing and modeling our spectroscopic results to interpret the measurements we make in the laboratory--for example, to determine what molecular structure is most consistent with a particular set of Raman data. A current research direction is development of the two-photon analog, resonance hyper-Raman spectroscopy, as a tool to explore the structures and dynamics of two-photon allowed states of molecules. Finally, the large enhancement of the scattering intensities observed for molecules adsorbed to the surfaces of silver and gold nanoparticles (surface enhanced Raman and hyper-Raman scattering) is being explored with an eye toward possible bioanalytical applications. We are developing new theoretical approaches to describing the enhancement of Raman scattering and other optical processes caused by coupling of the electronic transitions of molecules to the surface plasmon resonances of silver and gold nanoparticles, and carrying out experiments to test these theoretical descriptions. |
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Current group members ¨ Dr. Weinan Leng (postdoc) ¨ Marina Stavytska-Barba (graduate student) ¨ Vuchleang Taing (undergraduate student) |
