ORGN 670 |
| Controlling the product distribution in solution phase photochemical reactions is difficult due to the high mobility of the reactant molecules in the medium. One approach to bring about selective organic photochemical transformation is by suitably encapsulating the reactant molecule (guest molecule) within a host molecule. In this context, we have employed water soluble p-sulfonato calix[n]arenes (n=8, 1a – 1b and n = 6, 2a - 2b) as host molecules to control the outcome of the photolysis of benzoin alkyl ethers (3a – 3c) and the photodimerization of 4-stilbazoles (6a - 6d). Irradiation of the complexes of 3a – 3c within 1a and 2a resulted in formation of type-II (γ-hydrogen abstraction) product deoxybenzoin 4 as the major product, while aqueous solution irradiation of substrates 3a - 3c resulted in the formation of a mixture of products. Irradiation of the complexes of 6a - 6d within 1b and 2b resulted in formation of the syn-Head-Tail dimer 8a - 8d as the major product, while aqueous solution irradiations (in the absence of hosts 1b - 2b) resulted in isomerization to yield 11a - 11d as the major product and dimers 8a - 8d, 9a – 9d as minor products. Further, we are exploring the photochemistry of 1,2-bis-(n-pyridyl)-ethylenes within 1b and 2b. Results of the above studies will be presented.
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Physical Organic Chemistry: Calculations, Mechanisms, Photochemistry, and High-Energy Species
1:00 PM-4:40 PM, Thursday, 30 March 2006 Georgia World Congress Center -- C303, Oral
Division of Organic Chemistry |
