PHYS 387 |
| The photophysical properties of four selected novel azuliporphyrins in toluene have been investigated using photoacoustic calorimetry and emission spectroscopy. These methods are employed to measure the formation of the triplet excited state of these carbaporphyrinoids and their ability to mediate singlet oxygen production. All of the compounds have strong absorption bands in the neighborhood of 800 nm, which allows them to be considered as possible photodynamic therapy drugs. We have studied the effect of the loss of planarity as well as the presence of a heavy atom on the yields of the formation of the triplet excited state. The azuliporphyrins have low fluorescence yields (Φf = 2-3 x 10-3). Near infrared emission measurements revealed a band at about 1000nm extending to the region of singlet oxygen emission (1270 nm) interfering with its direct detection. The compounds produce small amounts of the triplet state (ΦTET = 20-60kJ/mol), however, the production of the triplet state is enhanced by the presence of a heavy atom. Finally, a radical trap, 2,2,6,6-tetramethyl-piperidin-4-one (TEMP) in combination with EPR was used to detect and measure any singlet oxygen produced. The azuliporphyrins produce small amounts of singlet oxygen (ΦΔ=0.09-0.2). |
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PHYS Poster Session - General Experiment
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster
Sci-Mix
Division of Physical Chemistry |