Tetra(1,1,4,4-tetramethyl-6,7-tetralino)porphyrazine as a novel luminescence sensor of laser-induced singlet oxygen generation in solutions

Absorption and fluorescence spectra and quantum yields of fluorescence and singlet oxygen generation were studied in air-saturated solutions of a newly synthesised dye, tetra(1,1,4,4-tetramethyl-6,7-tetralino)porphyrazine (TMTP), in benzene. Photophysical properties of TMTP are similar to those of previously studied tetra(4-tert-butyl) phthalocyanine (TBPc). However, the TMTP absorption and fluorescence bands are shifted to the longer wavelengths compared with those of TBPc. The laser-induced generation of singlet molecular oxygen ¹O₂ in TMTP solutions caused strong singlet oxygen-sensitised delayed fluorescence of the dye. The efficiency of singlet-oxygen-sensitised formation of excited TMTP molecules is two times higher than that of TBPc. It is shown that TMTP can serve as an efficient luminescence sensor of singlet oxygen.