Synthesis of Highly Luminescent Chiral Nanographene

Angew Chem Int Ed Engl. 2023 Jan 23;62(4):e202215367. doi: 10.1002/anie.202215367. Epub 2022 Dec 20.

Abstract

Chiral nanographenes with both high fluorescence quantum yields (ΦF ) and large dissymmetry factors (glum ) are essential to the development of circularly polarized luminescence (CPL) materials. However, most studies have been focused on the improvement of glum , whereas how to design highly emissive chiral nanographenes is still unclear. In this work, we propose a new design strategy to achieve chiral nanographenes with high ΦF by helical π-extension of strongly luminescent chromophores while maintaining the frontier molecular orbital (FMO) distribution pattern. Chiral nanographene with perylene as the core and two dibenzo[6]helicene fragments as the wings has been synthesized, which exhibits a record high ΦF of 93 % among the reported chiral nanographenes and excellent CPL brightness (BCPL ) of 32 M-1 cm-1 .

Keywords: Chirality; Circularly Polarized Luminescence; Helicene; Nanographene; Polycycles.