Structural and Aromaticity Control of [34]Octaphyrin(1.1.1.0.1.1.1.0) by Protonation and Deprotonation

The structural and aromaticity control of hexakis(pentafluorophenyl) [34]octaphyrin(1.1.1.0.1.1.1.0) 1 was examined by protonation and deprotonation. Protonation of 1 with methanesulfonic acid (MSA) induced a structural change from a figure-eight to a rectangular shape, accompanied by an aromaticity change from nonaromatic to strong Hückel aromatic. Deprotonation of 1 with tetrabutylammonium difluorotriphenylsilicate (TBAT) or fluoride (TBAF) produced a mono-deprotonated species with a similar figure-eight conformation and nonaromaticity.