An 18-Porphyrin Nanoring at the Size Limit for Global Aromaticity.

ABSTRACT: What is the size limit for global aromaticity? How large can a macrocyclic π-system be and still exhibit an aromatic ring current around its circumference? We address this question by investigating a π-conjugated butadiyne-linked 18-porphyrin nanoring (diameter 8 nm). This nanoring was synthesized by two different strategies: classical template-directed synthesis, using a radial template with 18 pyridyl binding sites, and Vernier templating, using a small hexapyridyl template. Both strategies are effective when the porphyrins have octyloxy side chains, but classical templating is more effective than Vernier templating when the porphyrins have bulky trihexylsilyl substituents. The size and shape of the nanoring were confirmed by scanning tunneling microscopy. ¹⁹F NMR oxidation ti

SUBMITTER: Holmes JM 

PROVIDER: S-EPMC12426941 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature