A series of tetraphenylethene-based benzimidazoles: syntheses, structures, aggregation-induced emission and reversible mechanochromism

作者：Zhang, Tengfei; Zhang, Ran; Zhang, Zhaoming; Ni, Zhonghai^*

来源：RSC Advances, 2016, 6(83): 79871-79878.

DOI：10.1039/c6ra16514a

• PHOTODYNAMIC THERAPY
• SOLID-STATE
• 2-PHOTON ABSORPTION
• SCHIFF-BASE
• PHOTOLUMINESCENCE
• FLUORESCENCE
• DESIGN
• PIEZOFLUOROCHROMISM
• HETEROCYCLES
• DERIVATIVES

Four tetraphenylethene-based benzimidazoles 5,6-R-2-(4-tetraphenyletheneyl)-1H-benzo[d]imidazoles (R = H (2a), Cl (2b), Br (2c) and CH3 (2d)) were conveniently synthesized in high yields by the cyclization reaction of 4-tetraphenylenthenealdehyde with phenylenediamines. These compounds were structurally characterized and their properties were analyzed by spectroscopy, electrochemistry, X-ray diffraction, thermal stability and theoretical studies. Single crystal X-ray diffraction analyses indicate that their molecular structures in the aggregated state are highly twisted conformations and there exist obvious cavities and/or interface gaps in their crystal packing structures. These four compounds exhibit typical aggregation-induced emission (AIE) properties with relatively high absolute fluorescence quantum yields (30.6-67.5%). These compounds also exhibit reversible mechanochromism behaviors with emission changes between light blue and yellow-green, which are due to the reversible morphological transformation between unconsolidated crystalline state and amorphous state. They are thermally stable with decomposition temperatures above 340 degrees C.

• 出版日期2016
• 单位中国矿业大学（北京）