Effect of Substituents of Corrole Derivatives on Generation of Singlet Oxygen

Abstract The correlation between the molecular structures of three corrole derivatives (PC: 5,10,15-triphenyl corrole, PFPC: 5,10,15-tris(pentafluorophenyl) corrole, MCPC: 5,10,15-tris(p-methoxycarbonylphenyl)corrole) and their efficiencies for singlet oxygen generation was studied. Introducing electron-withdrawing fluorine atoms into the PC moiety led to a significant enhancement in singlet oxygen generation and facilitated intersystem crossing (ISC) due to enhanced spin-orbit coupling. Cyclic voltammetry experiments revealed a desirable linear relationship between the quenching rate constants and the oxidation potentials of the three corrole derivatives, indicating that the substituent effect is a critical factor governing the oxidation potential of photosensitizers for singlet oxygen generation.