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