Synthesis and Properties of a Fused Antiaromatic Hydrocarbon By Oxidative Transformation of Carbacorrole Analogue

Abstract

Polycyclic aromatic hydrocarbons (PAHs) containing fused pyrrole moieties are known as unique nitrogen-doped pi-conjugated molecules, e.g., azacoronenes, which possess a large π-conjugated planar structure and show rich redox properties. The related molecules are thus expected to be applied to redox-responsible optoelectronic materials. Furthermore, PAH-based compounds containing [4n]π-electron antiaromatic segments, such as pentalene and indacene are contributed to the ambipolar semiconducting material applications due to the distinct high HOMO and low LUMO energy levels.In this work, we have synthesized and characterized a novel N-doped poly-antiaromatic hydrocarbon (PAH) by the oxidative transformation of a dibenzocarbacorrole isomer, namely, dibenzocorrorin (1). X-ray crystal structure of the fused product (2) revealed a highly planar pi-conjugated structure containing a unique diaza-dicyclopentaazulene moiety. The distinct 12pi antiaromatic resonance structure led to the emergence of a near-infrared band beyond 1000 nm in the absorption spectrum and facile redox properties determined in the cyclic voltammetry. Furthermore, crystalline compound 2 showed carrier mobility in the single-crystal organic field effect transistor.