四苯乙烯衍生物的合成及聚集诱导发光性质

Synthesis and Aggregation-Induced Emission Properties of Tetraphenylene Derivatives

摘要:

以2,2’-联吡啶为母体，通过Suzuki偶联反应在其5位和5’位引入四苯乙烯基团，设计合成了5-四苯乙烯-2,2’-联吡啶（Bpy-1TPE）和5,5’-二四苯乙烯-2,2’-联吡啶（Bpy-2TPE）两个具有聚集诱导发光（AIE）性质的荧光分子。经1HNMR、13CNMR及元素分析对目标产物进行了结构确认，对其紫外-可见吸收、荧光发射、聚集诱导发光、压致变色以及结构与性质之间的构效关系进行了研究。结果表明：相对于具有1个四苯乙烯单元的Bpy-1TPE，含2个四苯乙烯单元的Bpy-2TPE共轭体系更大且电荷呈对称分布，能隙宽度较低，其在二氯甲烷溶液中的最大发射峰由483红移至490 nm。Bpy-2TPE表现出明显的AIE性质和压致变色性质，其固体样品经研磨后最大发射波长可由485红移至500 nm。

Abstract:

Two fluorescent molecules with aggregation-induced emission (AIE) feature, 5-(4-(1,2,2-triphenylvinyl)phenyl)-2,2'-bipyridine (Bpy-1TPE) and 5,5'-bis(4-(1,2,2-triphenylvinyl)phenyl)-2,2'-bipyridine (Bpy-2TPE), were synthesized from 5-bromo-2,2'-bipyridine, 5,5'-dibromo-2,2'-bipyridine, and 4-(1,2,2-triphenylvinyl)phenylboronic acid via Suzuki coupling reaction. All proposed structures were characterized by 1HNMR, 13CNMR and elemental analyses. Their UV-vis absorption, fluorescence, AIE and piezochromic properties were investigated with the aim of understanding the structure-property correlations. Compared with Bpy-1TPE, Bpy-2TPE with two TPE units has a larger conjugation and a symmetrical charge distribution, which exhibited a lower energy gap width, and a red-shift of the emission from 483 to 490 nm in CH2Cl2. Bpy-2TPE showed obvious AIE and piezochromic properties, the emission maximum of its solid sample was red shifted from 485 to 500 nm after grinding.