A Fully Conjugated <i>Meso</i>-Boron-Substituted Porphyrinoid Combining Lewis Acidity with Redox-Switchable Aromaticity

The structural motif of porphyrin is relevant for many essential biological processes and has emerged as a versatile component of functional materials. Here, the authors report a thiophene-based porphyrinogen having electron-deficient boron atoms in all four <i>meso</i>-positions that exhibits redox-switchable aromaticity.