π‐Extended Heli(aminoborane)s with Highly Bright Circularly Polarized Luminescence and Narrowband Emission
Yang Yu, Chang Wang, Faan‐Fung Hung, Long Jiang, Chi‐Ming Che, Junzhi Liu
Abstract
Abstract Helical molecular carbons (HMCs) possess high absorption/luminescence dissymmetry factors ( g abs / g lum ) and significant luminescence quantum yield ( Φ lum ), resulting in a high circularly polarized luminescence (CPL) brightness ( B CPL ), which is essential for the development of CPL materials for practical applications. Herein, we designed and synthesized a series of boron‐nitrogen (BN)‐doped HMCs, named π‐extended heli(aminoborane)s ( E[10]HAB‐A , E[10]HAB‐B and E[10]HAB‐C ), consisting of laterally π‐extended [10]helicene skeleton with alternating N and B atoms at the inner rim. The aromaticity, electronic structures, and photophysical properties of E[10]HAB‐A/B/C were systematically investigated through experiments and theoretical calculations. E[10]HAB‐A/B/C displayed remarkable photophysical properties, including high molar extinction coefficient and bright narrowband emission. The isolated enantiomers of E[10]HAB‐A/B/C exhibited intense circular dichroism (CD) and CPL, in which E[10]HAB‐A shows g abs and g lum values up to 0.024 and 0.017, simultaneously with high Φ lum of 82 % and a narrow full width at half maximum of 16 nm. Accordingly, E[10]HAB‐A exhibits a B CPL as high as 583 M −1 cm −1 , which is the largest value among the reported BN‐doped HMCs. Our study indicates that inner rim BN‐doping and π‐extension are effective strategies to achieve high Φ lum and balanced g lum values in HMCs.