CHED 1443 |
| We investigated bimolecular photochemical reactions of prochiral chromophores such as acetophenone adsorbed in zeolites by Nuclear Magnetic Resonance (NMR.) Zeolites have proven to be very useful in controlling the outcome of photochemical reactions. This class of reactions holds promise as a more efficient and environmentally friendly method of synthesizing pharmaceuticals of specific spatial configurations. The product distribution in photochemical reactions we carried out in zeolites differ from the ones carried out in fluid media due to the close proximity of radical pairs trapped in the zeolites, which provide a very effective medium for a cage effect. In our study we investigated the photochemical reaction between acetophenone and cyclohexane adsorbed in zeolite Y. The result for this reaction is very selective when carried inside the zeolite leading to 1-cyclohexyl-1, phenylethanol as the only product. The investigation of photochemical reactions in zeolites benefits from the insights gained from the powerful solid state NMR methods. We used 13C Cross Polarization Magic Angle Spinning (CPMAS) NMR to follow the photochemical reaction of acetophenone and cyclohexane at different photolysis times. We investigated the motion of the methyl group in acetophenone adsorbed in zeolite Y by Solid State Deuterium NMR, which is very sensitive to motion. We conclude that knowledge of this kind about the microenvironment of the reactants and the product(s) provides the foundation for the rational design of better routes to controlled photochemical synthesis, with a view to improve on the current methods of manufacturing pharmaceuticals. |
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Undergraduate Research Poster Session: Physical Chemistry
2:00 PM-4:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Chemical Education |