Synthesis and Structural Characterization of Carbazole‐Tailored Luminescent Triarylmethyl Radical and its Stable Cation

Abstract

The development of novel luminescent radicals, characterized by their unique doublet emission, endows a significant challenge. In this study, we reported the synthesis of a luminescent neutral radical, BCzAnM‐R, tailored by two carbazolyl groups and an anthryl group to achieve a nonalternant structure. It exhibited near‐infrared emission with a peak at 1020 nm in toluene. Interestingly, its corresponding cation, BCzAnM‐C, was synthesized through an unconventional SnCl2‐mediated reduction‐aromatization‐oxidation reaction in one‐pot and gram‐scale. The cation demonstrated remarkable stability for up to weeks in ambient conditions and facilitated the silica‐gel chromatography isolation as an organic salt with SnCl3‐ as the counter ion. The carbazolyl groups effectively modulate molecular structures, photophysical properties, and stabilities. Notably, BCzAnM‐R represents the first luminescent triarylmethyl radical with two carbazolyl groups directly attached to the central carbon.