Multiple conformational changes of beta-tetraphenyl meso-hexakis(pentafluorophenyl) substituted [26] and [28]hexaphyrins(1.1.1.1.1.1).

Beta-tetraphenyl meso-hexakis(pentafluorophenyl) substituted [26]hexaphyrin is conformationally flexible between rectangular and figure-of-eight shapes and its two-electron reduced [28]hexaphyrin takes figure-of-eight conformations, which are changed, upon protonation, to twisted conformations with distinct Möbius aromaticity.