Porphyrin(2.1.2.1) organopalladium complexes as efficient singlet oxygen sensitizers

Abstract

Four new non-planar and non-aromatic porphyrin organopalladium complexes were synthesized. Conformational structures and optical and electronic properties of the obtained organopalladium complexes containing meso-substituted phenyl, p-tert-butylphenyl, or pentafluorophenyl groups were fully investigated. These complexes showed potent capacity for singlet oxygen (¹O₂) generation under blue-light irradiation, and the ¹O₂ quantum yields were in the range of 41%–56%, which were comparable to that of Ru(bpy)₃Cl₂ (57%), and such potency made these organopalladium complexes potential ¹O₂ photo sensitizers for photodynamic therapy.