Inversion Triggered by Protonation—A Rubyrin with Embedded α,β′‐Pyridine Moieties

Abstract

AbstractIncorporation of α,β′‐pyridine into a [26]hexaphyrin(1.1.0.1.1.0) frame resulted in formation of 29,33‐diaza‐A,D‐di‐p‐benzi[26]hexaphyrin (A,D‐di‐p‐pyrirubyrin), which acquires a strictly planar conformation with two nitrogen pyridine atoms directed to the center of the macrocyclic core. The mode of α,β′‐pyridine incorporation results in efficient 26‐electron π‐conjugation, as shown by the clear spectroscopic and structural aromatic features. The formation of the trication and tetracation through protonation is accompanied by a conformational flip of one or two pyridinium moieties to result in N‐confused or doubly N‐confused conformers of the original macrocyclic frame.