synthesis, singlet oxygen photogeneration and dna photocleavage of porphyrins with nitrogen heterocycle tails

Eight novel compounds were prepared by reaction of 5-(bromo- propoxyphenyl)-10,15,20-triphenylporphyrin with oxazole thiols, 1,3,4-oxadiazole thiols and 1,3,4-thiadiazole thiols, and their structures confirmed by UV-vis, IR, 1H-NMR, MS and elemental analysis. The assessment of indirectly measured 1O2 production rates against 5,10,15,20-tetraphenyl porphyrin (H2TPP) were described and the relative singlet oxygen production yields were：porphyrin 5 > porphyrins 1, 3, 4, 6-8, H2TPP > porphyrin 2. Porphyrin 4 and porphyrin 7 showed substantial photocleavage activities toward DNA, with over 75% cleavage observed at 40 µM. It suggested that these those porphyrins with nitrogen heterocycle tails are potential photosensitive agents.