Triply‐Linked N‐Confused Porphyrin Dimers: Cross Conjugation‐Mediated Expansion of π‐Conjugation

Abstract

ABSTRACT meso ‐ meso ′, α ‐ α ′, β ‐ β ′‐Triply‐linked N‐confused porphyrin (NCP) dimers were synthesized via stepwise oxidative coupling reactions of 5,10,15‐triaryl‐NCP, followed by nickel or silver metalation. The novel dimers possess extended π‐conjugation throughout the entire fused dimer structures, leading to Hückel 36π‐antiaromaticity and 38π‐aromaticity for the nickel and silver complexes, respectively. Theoretical investigations using the gauge‐including magnetically induced current (GIMIC) method reveal the pivotal role of NCP cross‐conjugation and NH tautomerism in forming the global π‐conjugation circuit. Redox reactions induce a unique switching of the π‐conjugation circuits, transforming delocalized π‐conjugation into localized π‐conjugation in the NCP macrocycle, giving rise to an antiaromatic domain at the bay area.