A Fully Conjugated Porphyrin-[36]Octaphyrin-Porphyrin Hybrid Tape Exhibiting Mobius Aromaticity

Directly meso-meso linked porphyrintetrabromo[36]octaphyrin-porphyrin hybrid trimer 10 was successfully synthesized via acid-catalyzed condensation reaction and subsequent oxidation. Zn-II-metalation of 10 induced transannular meso-meso bond formation to give Mobius aromatic bis-Zn-II octaphyrin 11, which was oxidized by DDQ/Sc(OTf)(3) to provide fully conjugated porphyrin[36]octaphyrin-porphyrin hybrid tape 12 as the first example of porphyrin tape exhibiting Mobius aromaticity. Hybrid tape 12 displays significantly red-shifted absorption and small electrochemical HOMO-LUMO gap, indicating the effective conjugation through the whole chromophores.