New photosensitizers based on cationic porphyrins with extended π-system have been synthesized. Synthetic strategy consists in the use of the Sonogashira cross-coupling reaction to form a conjugated π-system of the macrocycle. The prepared compounds exhibit an absorption peak at 660 nm with an extinction coefficient of ~60 000 M–1 cm–1; the singlet oxygen quantum yield and the 1-octanol–water partition coefficient were also determined. Absorption in the near-infrared region allows one to consider the obtained compounds as potential photosensitizers for photodynamic therapy.
Savelyeva et al. (Sat,) studied this question.