New perylenebisimide decorated cyclotriphosphazene heavy atom free conjugate as singlet oxygen generator.

Perylenebisimide-cyclotriphosphazene based inorganic-organic system was synthesized by a multistep procedure. The substitution reaction of asymmetric perylenebisimide (PBI) derivative with the hexachloroyclotriphosphazene (trimer) resulted in the formation of fully PBI decorated cyclotriphosphazene (5). The identity of newly synthesized compound (5) was confirmed by using 31P, 1H and 13C NMR spectroscopies and mass spectrometry. The photophysical (UV- Vis absorption, fluorescence emission, fluorescence lifetime and fluorescence quantum yield) and photochemical (the singlet oxygen generation, and photostability) properties of this conjugate were investigated as novel heavy atom free triplet photosensitizer. The singlet oxygen quantum yield of the PBI-cyclotriphosphazene (5) was calculated to be 0.86 which is good for a heavy atom free triplet photosensitizer. These results will add to the development of cyclotriphosphazene based heavy atom free singlet oxygen triplet photosensitizer systems for applications in organic oxygenation reactions.