Synthesis and a TD-DFT study of a series of novel 3-imidazolyl-substituted coumarin molecules with large Stokes shifts
作者:Zichun Zhou、Anna Zheng、Minzhe Wang、Yanhong Cui、Yongqian Xu、Hongjuan Li、Yujin Li、Shiguo Sun
DOI:10.1039/d3nj02365f
日期:——
salicylic aldehyde derivatives, ethyl acetoacetate and 2-aminopyridine derivatives, and exhibited strong blue fluorescence in non-polar solutions and large Stokes shift (184–210 nm) in polar solutions. All these were validated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). Furthermore, 3a-3d exhibited a solvatochromism effect and solid state fluorescence.
由水杨醛衍生物、乙酰乙酸乙酯和2-氨基吡啶衍生物合成了具有四个不同取代基的3-咪唑并[1,2-α]吡啶香豆素分子3a-3d,在非极性溶液中表现出强烈的蓝色荧光和大的斯托克斯位移( 184–210 nm) 在极性溶液中。所有这些都使用密度泛函理论(DFT)和瞬态密度泛函理论(TD-DFT)进行了验证。此外,3a-3d表现出溶剂化显色效应和固态荧光。结果表明,在香豆素的3个位置引入3-咪唑并[1,2-α]吡啶基团构建了不对称电子结构,诱导了非辐射能量增强的分子内电荷转移(ICT),导致大分子斯托克斯位移。同时,通过在咪唑并[1,2-α]吡啶中引入给电子基团,可以缩小HOMO(最高占据分子轨道)-LUMO(最低未占据分子轨道)间隙,从而增强ICT,进一步增加斯托克斯位移,提出了一种有前景的新颖模型,可以实现香豆素染料开发的大斯托克斯位移。