Porphyrin(2.1.2.1) organopalladium complexes as efficient singlet oxygen sensitizers

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 ( 1 O 2 ) generation under blue-light irradiation, and the 1 O 2 quantum yields were in the range of 41%-56%, which were comparable to that of Ru(bpy) 3 Cl 2 (57%), and such potency made these organopalladium complexes potential 1 O 2 photo sensitizers for photodynamic therapy. Non-planar and non-aromatic porphyrin(2.1.2.1) organopalladium complexes show singlet oxygen quantum yields as high as 56%, slightly lower than that of Ru(bpy) 3 Cl 2 and some clinically evaluated porphyrinoid 1 O 2 sensitizers.