The last decade has witnessed the emergence of a unique class of transition metal complexes -the 5d metallocorroles. Their uniqueness derives from their size-mismatched nature, which involves a large 5d ion encapsulated by a sterically constrained, macrocyclic corrole ligand. In spite of the steric strain inherent in their structures, the middle and late 5d transition metal (Re, Os, Ir, Pt, and Au ) corroles have proved thermally and photochemically rugged. Furthermore, their photophysical properties are conducive to applications as photosensitizers, most notably in photodynamic therapy and oxygen sensing. Interestingly, in the course of our photophysical studies on 5d metallotriarylcorroles, we repeatedly observed somewhat higher phosphorescence quantum yields for tris{(p-trifluoromethyl)phenyl}corrole complexes than for their more electron-rich counterparts. The observation made us wonder whether fluorinated substituents might have a beneficial effect on the luminescence properties of 5d metallocorroles. A photophysical study was accordingly carried out on the complexes depicted in Chart 1, except for the M = OsN, Ar = C6F5 case, which was not studied because of synthetic difficulties. We found that fluorinated substituents indeed appear to have a beneficial effect on the luminescence properties of the complexes, significantly increasing both the phosphorescence quantum yields and triplet decay times.