Biphenyl Diimide Based Novel Blue Emitters with Aggregation-Induced Blue-Shifted Emission Characteristics

作者：Wang, Zhijun; Song, Ruitong; Zhang, Yueyan; Zhang, Tao; Zhu, Xiangyu; Zeng, Jiajie; Zhang, Weidong; Zhao, Zujin; Yan, Ni; He, Gang^*

来源：ChemPhotoChem, 2020, 4(1): 59-67.

DOI：10.1002/cptc.201900202

• aggregation induced emission
• conjugated diimides
• electroluminescence
• OLED
• seven-membered rings

Two biphenyl diimide (BPI) monomers containing seven-membered imide rings and four conjugated aromatic diimides, BPI-Ph, BPI-Th, BPI-Se and BPI-Py, with unique aggregation-induced blue-shifted emission (AIBSE) properties, are reported. The crystal structures revealed that the imide backbones were twisted, leading to weaker 1D pi-stacking, which makes the compounds very different from other reported imides. Their cyclic voltammetry, UV/Vis absorption and fluorescence spectra, as well as DFT calculations, were investigated in detail. The photophysical properties and aggregation behaviors of BPI-Ph, BPI-Th, BPI-Se and BPI-Py in mixtures of THF/water were systematically studied. The intriguing AIBSE of the BPI-containing compound was attributed to the lower reorganization energies in aggregates than in the solution phase, ascribed to the lack of pi-stacking resulting from the twisted seven-membered rings, restricted intramolecular rotation (RIR) and weak intermolecular interactions in the solid state. Additionally, BPI-Py-based OLEDs exhibited good performance of L-max, eta

• 单位
  长安大学; 西安交通大学