【作者】 张亚桐；

【导师】 卢丽萍； 王爱；

【作者基本信息】 山西大学 ， 无机化学， 2023， 博士

【摘要】 近年来,兼具有机配体和无机金属特点的配合物,表现出优异的物理和化学性质,成为研究热点之一。其中,拥有丰富氢键作用的氨基酸衍生物配合物,不仅为搭建超分子化合物提供了设计思路,而且为构筑具有高灵敏度的荧光传感材料提供了结构基础。本论文主要选取氨基酸衍生物作为配体,分别与过渡金属和稀土金属离子反应,在溶剂热条件下,合成并筛选出具有荧光传感性能的配合物,并对其作用机制进行深入探讨。目的是获得对离子或分子具有高选择性的荧光传感材料,为水样中重金属离子和残留药物分子的可视化、快速、便携检测提供有效的实验方法,为保护生态系统平衡和人类健康提供实验基础。具体研究内容如下:1.基于1,4-双（（L-丝氨酸）甲基）苯（H₂bsmb）、（4-（1H-咪唑-1-基）苄基）-L-谷氨酸（H₂ibga）、N-（4-羧基苄基）-L-天冬氨酸（H₃caa）与金属离子[Co（Ⅱ）、Ni（Ⅱ）、Cu（Ⅱ）、Zn（Ⅱ）、Cd（Ⅱ）和Ln（Ⅲ）],在不同的投料比、溶剂和p H条件下,使用溶剂热法合成了17种结构新颖的配合物。分析晶体结构和圆二色光谱发现,配合物1-4很好的继承了配体H₂bsmb的手性,证实H₂bsmb易合成对映纯手性配合物。对比配体H₂ibga和配合物5的结构及圆二色光谱发现,配合物5中配体发生环化,为合成含有活性环状肽结构的配合物提供了设计思路。配合物7-12的晶体结构各异（其中12-17是同构配合物）,配体H₃caa共表现出7种不同的配位模式,由此可见使用含三个羧基的H₃caa合成的配合物结构多样。除此之外,通过配合物1-17的晶体信息表和Hirshfeld面分析,从数值和图样两方面,系统且直观地分析了配合物1-17中的弱相互作用（氢键和π···π）,为功能型超分子配合物的合成提供了实验基础。2.经过荧光实验的筛选发现,由H₂bsmb,H₃caa和含有d¹⁰电子构型的金属离子合成的三种配合物4,10和11,它们的荧光不仅都具有良好的水稳定性和耐酸碱性,而且配合物11可作为水体系中的热敏传感器。配合物4和11可以特异性识别水环境中的Tb（Ⅲ）离子,配合物10可特异性的识别四环素（TC）,检出限分别是11.4 n M,16.9 n M和5.53 n M。通过对比配合物及其荧光试纸条添加分析物前后的颜色变化,为Tb（Ⅲ）离子和TC的目视检测提供了定量分析手段。其作用机制分别是,配合物4和11的能量转移到Tb（Ⅲ）离子,进而将其敏化并出现Tb（Ⅲ）离子的特征峰;配合物10在传感过程中存在共振能量转移及光诱导电子转移（PET）,使其在530 nm处出现TC的特征峰,而420 nm处配合物的峰减小的现象,进而达到识别TC的效果。3.我们还筛选出三种多功能荧光材料,分别为:实现了Ce（Ⅲ）和Cu（Ⅱ）双向检测的配合物2;对TC、Fe（Ⅲ）和AA（抗坏血酸）具有多响应检测的配合物5以及实现Cr₂O₇^2-、Cr O₄^2-、TC和CTC（金霉素）双模式检测（荧光和目视）的配合物17。其中,配合物2检测Ce（Ⅲ）和Cu（Ⅱ）的检出限分别为0.388 n M和8.134μM。其作用机制是,配合物2上未配位的羧基氧原子分别与Ce（Ⅲ）和Cu（Ⅱ）之间存在弱相互作用力,进而促进了电子从配合物2转移到Ce（Ⅲ）离子,并且Cu（Ⅱ）部分填充的d轨道与配合物2之间存在电荷转移或能量转移。配合物5检测TC、Fe（Ⅲ）和AA的检出限分别为4.42 n M,3.49 n M和0.38μM。其作用机制是:在检测过程中,配合物5与TC、Fe（Ⅲ）和AA之间存在激发态能量的竞争性吸收和共振能量转移的协同作用,且对Fe（Ⅲ）离子具有吸附作用。配合物17检测Cr₂O₇^2-、Cr O₄^2-、TC和CTC的检出限分别为3.66 n M、5.45 n M、0.25μM和0.24μM。其荧光猝灭机制为:在检测过程中,配合物17与Cr₂O₇^2-、Cr O₄^2-、TC和CTC存在激发态能量的竞争性吸收和共振能量转移,并且配合物17的中心金属Tb（Ⅲ）离子与分析物Cr（Ⅵ）离子之间存在静电相互作用。更多还原

【Abstract】 In recent years,coordination complexes possess the characteristics of organic ligands and inorganic metals,and have become a hot research topic due to their excellent physical and chemical properties.Among them,complexes derived from amino acid usually have abundant hydrogen bond interactions,which not only provide design ideas of synthesizing supramolecular compounds,but also act as the structural basis for designing fluorescent sensors with high sensitivity.In this dissertation,amino acid derivatives are selected as ligands to react with transition metal and rare earth metal ions,respectively.Complexes with fluorescence sensing properties are synthesized under solvothermal condition,and their sensing mechanisms are explored in detail.Fluorescence sensors constructed from amino acid derivatives show high selectivity,visualization,rapidity towards heavy metals cations and residues of the organic molecules in aqueous system,which provide experimental and theoretical basis for protecting ecosystem balance and human health.All researches include:1.Seventeen novel complexes were synthesized based on1,4-bis（（L-serine）methyl）benzene（H₂bsmb）,（4-（1H-imidazol-1-yl）benzyl）-L-glutamic acid（H₂ibga）,N-（4-carboxylbenzyl）-L-aspartic acid（H₃caa）and different metal ions[Co（Ⅱ）,Ni（Ⅱ）,Cu（Ⅱ）,Zn（Ⅱ）,Cd（Ⅱ）and Ln（Ⅲ）]under solvothermal condition with different molar ratios,solvents and p H.Complexes 1-4 inherit the chirality from ligand H₂bsmb by single-crystal structure and CD spectra analysis,indicating enantiomeric purity complexes can be synthesized easily by H₂bsmb.The ligand H₂ibga cyclized in complex 5can be found by comparing with the structure and CD spectra of ligand and complex 5,which provides a design idea of complexes containing active cyclic peptide structure.Ligand H₃caa has seven different coordination modes in complexes 7-12（complexes12-17 were isomorphic）,implying complexes based on H₃caa have various structures.In addition,the weak interactions（hydrogen bonds andπ···π）in complexes 1-17 were analysized from values and graphics from crystal information and Hirshfeld surface,which provide experimental clues for synthesizing supramolecular complexes.2.Three complexes（4,10 and 11）were synthesized by H₂bsmb,H₃caa and metal ions with d¹⁰ electronic configuration and selected by fluorescence experiment.These complexes have good stabilities in water and acid and alkali resistance,in which complex11 might act as a thermal sensor in aqueous.Complexes 4 and 11 can specifically recognize Tb（Ⅲ）ions in aqueous system with low detection limits（LODs）of 11.4 n M and16.9 n M,respectively.Complex 10 can specifically detect tetracycline（TC）with LOD of5.53 n M.It provides a quantitative and visual method for detecting Tb（Ⅲ）ions and TC by analyzed color change of complexes and their strips before and after adding analytes.The sensing mechanisms of complex 4 and 11 are the energy transferred from complexes 4 and11 to Tb（Ⅲ）ions,respectively.There are resonance energy transfer and photo-induced electron transfer（PET）during the process of complex 10 in sensing TC,resulting in the characteristic peak of TC appeared at 530 nm and the peak of complex 10 at 420 nm decreased.3.We screened out three multifunctional fluorescent materials.For example,complex2 realizes bidirectional detection of Ce（Ⅲ）and Cu（Ⅱ）ions,complex 5 shows the multi-response detection behavior towards TC,Fe（Ⅲ）and AA,and complex 17 could sense Cr₂O₇^2-,Cr O₄^2-,TC and CTC by fluorescence and visual methods respectively.Among of them,complex 2 selectively senses Ce（Ⅲ）and Cu（Ⅱ）ions with LODs of0.388 n M and 8.134μM,respectively.The sensing mechanisms of complex 2 are the weak interactions exist between uncoordinated carboxylic group of complex 2 and Ce（Ⅲ）&Cu（Ⅱ）ions in solution,which promotes electrons transfer from complex 2 to Ce（Ⅲ）ions.And there is charge transfer or energy transfer between partially filled d orbital of Cu（Ⅱ）and complex 2.Complex 5 can sense TC,Fe（Ⅲ）and AA with LODs of 4.42 n M,3.49 n M and 0.38μM,respectively.There are competitive absorptions of excited state energy and resonance energy transfer in the process of complex 5 detection these three analytes.Besides,Fe（Ⅲ）ions may be adsorbed when it quenched the fluorescence intensity of 5.Complex 17 displays excellent sensing ability to Cr₂O₇^2-,Cr O₄^2-,TC and CTC with LODs of 3.66 n M,5.45 n M,0.25μM and 0.38μM,respectively.The competitive absorption of excited state energy and resonance energy transfer exists during the process of complex 17 sensing,and electrostatic interaction between Tb（Ⅲ）ions of complex 17and Cr（Ⅵ）may also contribute to the quenching effect.更多还原