Three green-emitting compounds 1–3 based on 2-aryl-3-cyanobenzofuran fluorophore tethered with aggregation-induced emission active (AIE-active) tetraphenylethene (TPE) were designed and synthesized. p-Methoxyphenyl (PMP) was installed on the 5-, 6-, and 7-positions of 2-aryl-3-cyanobenzofuran for systematically investigating the substituent effect on their photophysical properties in solutions, nanoparticles, films, crystals, as well as powders. The aggregation-caused quenching (ACQ) problem arising from the π–π stacking between fluorophores was surmounted by covalently bonding the TPE unit. Thus, these compounds emitted green light in solids, and the film's quantum yield approached 50.1%. Red-shifted mechanochromism was observed for the crystalline state with a small crystal density. The best OLED performance was achieved using the compound with PMP occupied at the 6-position of 2-aryl-3-cyanobenzofuran, which possessed the longest efficient conjugation length.

中文翻译：

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通过束缚四苯乙烯以实现绿色电致发光来打开非发射性2-芳基-3-氰基苯并呋喃的固体发射物†

设计并合成了基于2-芳基-3-氰基苯并呋喃荧光团的3种绿色发射化合物1-3，并附有聚集诱导的发射活性（AIE活性）四苯乙烯（TPE）。p-甲氧基苯基（PMP）安装在2-芳基-3-氰基苯并呋喃的5、6和7位上，用于系统研究取代基对其在溶液，纳米颗粒，薄膜，晶体和粉末中的光物理性能的影响。通过共价键合TPE单元克服了由荧光团之间的π–π堆积引起的聚集引起的猝灭（ACQ）问题。因此，这些化合物在固体中发出绿光，薄膜的量子产率接近50.1％。对于具有小的晶体密度的晶体状态，观察到红移的机械致变色。使用PMP在2-芳基-3-氰基苯并呋喃的6位上占据的PMP化合物，可以获得最佳的OLED性能，该化合物具有最长的有效缀合长度。