Cover Feature: Quest for the Most Aromatic Pathway in Charged Expanded Porphyrins (Chem. Eur. J. 6/2023)

The aromaticity of charged expanded porphyrins turns out to be much more complex to study than that of their planar neutral analogues. In particular, identifying the most conjugated circuit is no longer straightforward. In addition to planarity, the protonation and deprotonation of porphyrinoids play an important role in determining their aromaticity. We have demonstrated that the largest charged porphyrins do not present a clear main conjugation pathway. Among the preferred aromatic indices, AVmin ends up being the most useful tool for recognizing the most aromatic path. We can relate the difficulty of finding the most conjugated path of a porphyrin to the number of pieces in a puzzle. Thus, the neutral state of the [36]octaphyrin is represented as a puzzle with few pieces; the protonated and deprotonated states are presented as puzzles with more pieces to indicate that they are more difficult to complete. More information can be found in the Research Article by M. Torrent-Sucarrat, E. Matito, M. Alonso, and co-workers (DOI: 10.1002/chem.202202264).