Möbius Aromaticity in N-Fused [24]Pentaphyrin upon Rh(I) Metalation

N-fused pentaphyrins (NFP5), stable forms of meso-aryl pentaphyrins, are interesting platforms to realize Hückel aromaticity, nonaromaticity, and Möbius aromaticity depending upon the number of π-electrons, meso-substituent, and metalation. Remarkably, Rh(I) complex of pentakis(pentafluorophenyl) substituted [24]NFP5 has been characterized as a Möbius aromatic macrocycle by the crystal structure, 1H NMR spectrum, NICS calculation, and two-photon absorption (TPA) cross section. This system is, to the best of our knowledge, the smallest Möbius aromatic molecule with a distinct diatropic ring current characterized so far. This work demonstrates the great potential of our synthetic strategy toward Möbius aromatic molecules as well as the possible use of TPA value as a quantitative measure of aromaticity.