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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 acceptor molecules, 1,4-bis [2- (4-pyridyl) vinyl] benzene, were synthesized in high yields by the classical Witting-Horner reaction and Sonogashira cross-coupling reaction The structures and spectral properties of the compounds were studied.The structures of the compounds were characterized by NMR, elemental analysis and mass spectrometry. The crystal structure showed that the configuration of the hydrogen bonding assembly changed due to the steric effect of ortho-aromatic acetylene groups The results of UV-visible spectroscopy combined with time-dependent density functional theory (TDDFT) show that the target compounds exhibit strong π → π * and ICT transition absorption in the ultraviolet region, and the fluorescence spectra show that the conjugated compounds increase with increasing conjugate system Their emission peaks have a redshift tendency and contribute to the formation of π-π stacking between the molecules.These results will provide some synthetic basis for the subsequent study on the regioselectivities and photocyclization of hydrogen-bonding self-assembly and Theoretical basis.