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.