Phthalocyanines: unique coordination for unique properties

Photodynamic therapy is one of the main applications of phthalocyanines, whose properties, if finely tuned, can be optimized depending on the targeting drug delivery system, the therapeutic target, and the expected outcome. Photodynamic therapy can be improved with better generation of singlet oxygen and other reactive oxygen species, often promoted by heavy atoms, and specific tumor accumulation, which can be improved by drug delivery systems. On the other hand, azobenzene triplet photoswitching needs systems shielded from oxygen.

Besides the substitution pattern, the coordination of different metals at the center of the phthalocyanine’s macrocycle is a versatile manner to improve their properties.