Zou Yang, Yu Mingxin, Miao Jingsheng, Huang Taian, Liao Shuokun, Cao Xiaosong, Yang Chuluo
Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University Shenzhen 518060 PR China
Chem Sci. 2023 Feb 28;14(12):3326-3331. doi: 10.1039/d3sc00246b. eCollection 2023 Mar 22.
Multiple resonance (MR) molecules based on a B/N polycyclic aromatic framework are the cutting-edge materials in the field of organic light-emitting diodes (OLEDs) owing to their superb photophysical properties. Tailoring the MR molecular framework with various functional groups toward ideal properties has become an emerging topic in the field of materials chemistry. Dynamic bond interactions are versatile and powerful tools in regulating the properties of materials. Herein, the pyridine moiety, which presents high affinity to form dynamic bond interactions such as hydrogen bonds and N→B dative bonds, was introduced into the MR framework for the first time, and the designed emitters are synthesized in a feasible way. The introduction of the pyridine moiety not only maintained the conventional MR properties of the emitters, but also endowed the emitters with tunable emission spectra, narrowed emission, enhanced photoluminescence quantum yield (PLQY), and intriguing supramolecular assembly in the solid state. Thanks to the overall superior properties brought by the hydrogen-bond promoted molecular rigidity, green OLEDs based on the emitter exhibit excellent device performance with external quantum efficiency (EQE) up to 38% and a small FWHM of 26 nm, together with good roll-off performance.
基于B/N多环芳烃骨架的多共振（MR）分子因其优异的光物理性质而成为有机发光二极管（OLED）领域的前沿材料。通过各种官能团对MR分子骨架进行剪裁以获得理想性能已成为材料化学领域的一个新兴课题。动态键相互作用是调控材料性能的通用且强大的工具。在此，首次将对形成氢键和N→B配位键等动态键相互作用具有高亲和力的吡啶部分引入到MR骨架中，并以可行的方式合成了所设计的发光体。吡啶部分的引入不仅保持了发光体的传统MR性质，还赋予发光体可调谐的发射光谱、窄化发射、增强的光致发光量子产率（PLQY）以及固态下有趣的超分子组装。得益于氢键促进的分子刚性所带来的整体优异性能，基于该发光体的绿色OLED展现出优异的器件性能，外部量子效率（EQE）高达38%，半高宽（FWHM）小至26 nm，同时具有良好的滚降性能。
