ABSTRACT

The synthesis and characterisation of tripodal ligand 1 containing 1,3,5-benzenetricarboxamide core and diethyl 4-(phenylethynyl)pyridine-2,6-dicarboxylate is described. The crystal structure of the intermediate tripodal molecule 7 exhibits an unusual staggered hydrogen-bonded chain motif instead of the anticipated helical assembly. We studied the basic photophysical properties of 1 in solvents of various polarity including CH₃OH, CH₃CN, DMSO, and CHCl₃. The self-assembly experiments between 1 and Eu(CF₃SO₃)₃⋅6H₂O confirmed the formation of metal-ligand self-assembly species in the solution of CH₃CN. It was also shown that the excitation of the Eu(III)-centred emission in such species occurred through the energy transfer from the ligand acting as an antenna to the metal centre. The binding constant values were evaluated using the nonlinear regression analysis software SPECFIT®, and their values correspond to those previously observed for the assemblies between 2,6-dipicolinic acid derivatives and lanthanide ions. This work describes the synthesis of tripodal 1,3,5-benzenetricarboxamide ligand with dipicolinic acid units and its binding with Eu(III) ions in solution. The photophysical properties of the target tripodal ligand were studied in solvents of various polarity. The self-assembly experiments between the ligand and Eu(III) ions in solution confirmed the formation of luminescent metal-ligand self-assembly species.

摘要

描述了含有 1,3,5-苯三甲酰胺核和 4-(苯基乙炔基)吡啶-2,6-二甲酸二乙酯的三足配体1的合成和表征。中间三足分子7的晶体结构表现出不寻常的交错氢键链图案，而不是预期的螺旋组装。我们研究了1在各种极性溶剂中的基本光物理性质，包括CH ₃ OH、CH ₃ CN、DMSO和CHCl ₃。1与Eu(CF ₃ SO ₃ ) ₃ ⋅6H ₂的自组装实验_{O证实了CH 3}溶液中金属配体自组装物种的形成CN. 研究还表明，此类物质中以 Eu(III) 为中心的发射的激发是通过从充当天线的配体到金属中心的能量转移而发生的。使用非线性回归分析软件SPECFIT®评估结合常数值，其值对应于先前观察到的2,6-吡啶二甲酸衍生物和镧系离子之间的组装的值。这项工作描述了具有吡啶二羧酸单元的三足 1,3,5-苯三甲酰胺配体的合成及其与溶液中的 Eu(III) 离子的结合。研究了目标三足配体在不同极性溶剂中的光物理性质。溶液中配体与Eu(III)离子之间的自组装实验证实了发光金属-配体自组装物种的形成。