ORGN 413 |
| Daniel S. Tyson1, James D. Kinder2, and Michael A. Meador2. (1) Materials Division, Ohio Aerospace Institute and NASA Glenn Research Center, 21000 Brookpark Road, MS 49-1, Cleveland, OH 44135, (2) Materials Division, NASA Glenn Research Center, 21000 Brookpark Road, MS 49-3, Cleveland, OH 44135 |
| Symmetrically substituted dioxapyrenes were synthesized in three steps from 4,8-ditoluoyl-1,5-dihydroxynaphthalene. The choice of functional group had a noticeable impact on the reaction sequence. In general, the first step was a traditional base-catalyzed ether synthesis, under phase-transfer conditions, in which two equivalents of substituted benzyl bromide were added to the starting material. Treatment of the resulting ethers with tetrabutylammonium cyanide produced, in varying degrees, hydrated dioxapyrene derivatives. The final step, acid-catalyzed dehydration, resulted in a new class of substituted dioxapyrenes. Optical spectroscopy studies were preformed to evaluate potential use as fluorescent probes. The dicyano-substituted dioxapyrene, 2,7-bis(4-cyanophenyl)-4,9-bis(4-methylphenyl)-1,6-dioxapyrene, revealed a broad absorption centered near 450 nm (e=31,900 M-1cm-1) in THF with a corresponding fluorescence at 619 nm (Ff=0.011). The luminescence was found to be solvatochromic (lmax=619 nm-644 nm) with single exponential lifetimes of less than 1.3 ns. Complete synthetic details and optical properties, including competitive photochemical reactions, will be presented. |
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Materials, Devices, and Switches
8:00 AM-12:00 PM, Wednesday, March 31, 2004 Anaheim Convention Center -- 303A, Oral
Division of Organic Chemistry |