1,4-双[2-(4-吡啶基)乙烯基]苯衍生物的合成、光谱性质及理论研究

Synthesis, Spectral Properties and Theoretical Studies of 1,4-Bis[2-(4-pyridyl)ethenyl]benzene Derivatives

通过经典的Witting-Horner反应及Sonogashira交叉偶联反应以较高的产率合成得到4个不对称型氢键受体分子1,4-双[2-(4-吡啶基)乙烯基]苯衍生物,并对其结构及光谱性质开展了研究.系列化合物均通过核磁、元素分析及质谱的表征,晶体结构表明由于苯环邻位芳环乙炔基的空间效应导致氢键组装的构型发生改变.紫外可见光谱结合含时密度泛函理论(TDDFT)计算表明目标化合物在紫外区域均呈现出强烈的π→π*及ICT跃迁吸收.荧光光谱表明随着共轭体系的逐渐增大也导致了它们的发射峰有一个红移的倾向,且有利于分子之间形成π-π堆积.以上结果将为后续的氢键自组装的区域选择性及光照环化实验研究提供了一定的合成基础及理论依据.

Four asymmetric hydrogen-bond acceptors of 1,4-bis[2-（4-pyridyl）ethenyl]benzene derivatives with higher yields were synthesized through the classical Witting-Horner and Sonogashira cross-coupling reactions, and their structures and spectral properties were investigated. The series of compounds all have been characterized by NMR, MS and element analysis. Crystal structures indicated that the conformation of hydrogen-bond self-assemble may be change due to the hindrance effect from the arylacetyl group in o-position of benzene. UV-Vis spectra combined with time-dependent density functional theory （TDDFT） calculation results showed that target compounds all display a strong π→π＊ and ICT transition absorptions. Fluorescence spectrum indicated that gradual increasing of conjugate systems make their emission peak tend to a red shift, which is conducive to π-π accumulation. Above results will provide certain synthetic basis and theoretical foundation for subsequent studies about regioselectivity of hydrogen-bond self-assemble and cyclization reactions from light.