Chemical Oxidation Induced Aromaticity Switching of -Ethylene Bridged [38] Octaphyrin (1.2.1.0.1.2.1.0) with NIR Absorption.

We report the syntheses, spectroscopic analyses, and solid-state structural evidence of a quasi-planar aromatic [38] -ethylene bridged octaphyrin (1.2.1.0.1.2.1.0) exhibiting NIR absorption. The chemical oxidation using an appropriate oxidant led to unique π reconstruction via amine-imine conversion and/or C-oxygenation of the inverted thiophene rings resulting in weakly antiaromatic or nonaromatic [36] octaphyrins with preserved -conformation of the ethylene moieties. The aromatic nature of the studied octaphyrins is supported by GIMIC calculations of the magnetically induced ring current density.