Synthesis and unusual properties of the first 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraalkylporphyrin

The new perhalogenated porphyrin 2,3,7,8,12,13,17,18- octabromo-5,10,15,20-tetrakis(trifluoromethyl)porphinatonickel(II) exhibits several striking features, including an extremely ruffled macrocycle with a very short Ni–N distance, an unusually red-shifted optical spectrum, and, surprisingly, hindered rotation of the meso-trifluoromethyl substituents (ΔG‡278 = 47 kJ mol–1).