M. Gierszewski, M. Falkowski, L. Sobotta, M. Stolarska, Ł. Popenda, S. Lijewski, B. Wicher, G. Burdzinski, J. Karolczak, S. Jurga, M. Gdaniec, E. Tykarska, M. Sikorski, J. Mielcarek, T. Goslinski
Porphyrazines possessing isophthaloxyalkylsulfanyl substituents in the periphery were synthesized and subjected to various photophysical studies, including optical absorption and emission measurements. The fluorescence lifetimes of four porphyrazine derivatives were measured in different organic solvents. The results of the steady-state and time-resolved measurements of magnesium porphyrazines with different alkyl groups between sulfanyl substituent and isophthaloxy group were compared with those of demetallated porphyrazine. The porphyrazine macrocycles exhibit interesting solvatochromic effects, which are described by Δf solvent polarity scale and four-parameter scale proposed by Catalán. Transient absorption spectroscopy was used to obtain the values of triplet lifetime for magnesium porphyrazine with 2-(3,5-dibutoxycarbonylphenoxy)ethylsulfanyl substituents. Values of singlet oxygen generation quantum yields were obtained in different organic solvents using various techniques, including the characteristic emission of the singlet oxygen at 1270 nm with the steady-state and time-resolved approaches.