Influence of meso substituents on electronic states of (oxoferryl)porphyrin pi-cation radicals

The syntheses and characterization of a series of (oxoferryl)porphyrin pi-cation radicals are presented. The radicals were prepared from porphyrins tetrakis-5,10,15,20-(2,6-dichlorophenyl)-, 5-(2-chloro-6-nitrophenyl)-10,15,20-tris(2,6-dichlorophenyl)-, and 5-(2,6-dinitrophenyl)-10,15,20-tris(2,6-dichlorophenyl)porphyrins. The results showed that the resonance Raman marker v2 and v11 do not shift down in frequency on oxidation. There was also a deviation from the usual pattern in unpaired electron spin density distribution.