新型MOFs材料用于水分子传感研究

发布时间：2018-05-07 20:58

本文选题：金属-有机网格 + 水分子传感　；参考：《东华理工大学》2017年硕士论文

【摘要】：材料,是人类物质文明的先导和基础,是推动社会发展的直接动力,是开发新型能源和治理环境污染的重要保障。它在人类历史发展的长河中扮演着重要的角色,是人类生存和生活不可或缺的部分。传感材料,作为功能材料的一大“分支”,受到研究者的广泛关注。而无机-有机框架材料(metal-organic frameworks,MOFs)因其骨架的刚性、永久的孔性、结构的多样性以及同时兼备的高化学和热稳定性,成为了传感材料中的“明日之星”。以溶剂化显色和发光性能为主,包括干涉测量法,局域表面等离子体共振光谱法(LSPR)、石英晶体微量天平法(QCM)、表面声波传感(SAW)、微型悬臂梁传感(MCL)、电化学阻抗法、胶体晶体(CC)等在内的信号转导方式可以满足对不同的被分析物分子产生信号响应,而不用担心MOFs材料的性质和结构,在有机小分子、蒸汽和气体、阴/阳离子等研究领域取得了重大的进展。鉴于此,本论文设计制备了两例新型的配合物,并对它们进行了结构表征,热稳定性分析,水溶剂传感,吸附性能以及其中一个发光配合物的荧光寿命,量子产率和另一个具有溶剂化显色效应的配合物的紫外-可见光谱光谱等研究,具体如下:通过混合溶剂热的方法,1,3,5-均三苯甲酸配体和酰胺配体L1与金属Zn(Ⅱ)通过自组装制备出一例在b方向上具有一维螺旋结构的六方配合物MOF-1。对其单晶结构解析,结果显示MOF-1存在两种对映的手性结构,分别结晶在P6422和P6222两种空间群,并互为外消旋体。Platon和Topos软件计算MOF-1的溶剂占有率为32.8%且具有四重自穿插结构。在外加的机械压力下,能使原本信号不强的样品可以经研磨来提升其荧光强度、荧光寿命及量子产率。并且对不同有机溶剂中的含水量进行分析,结果显示研磨后的样品能对不同浓度产生三种不同的荧光响应机制:在较低浓度下,对水分子表现出随浓度增加荧光强度增强的信号变化机制;在常规浓度下,对水分子表现出发射波长随浓度增加而红移的信号变化机制;在较高浓度下,对水分子表现出随浓度增加荧光信号猝灭的变化机制。另外对MOF-1的吸附性能研究发现研磨的样品能通过水分子来调控对C2H2,C2H4,CO2吸附能力。通过水热合成法,4,4'-联吡啶和L2配体与金属Co(Ⅱ)通过自组装制备出一例水分子参与配位,具有一维螺旋结构的六方配合物MOF-2。单晶结构解析显示MOF-2同样存在两种对映的手性构型,分别结晶在P61和P65两种空间群,并互为外消旋体。实验发现,样品在200℃真空热处理下,容易失去配位水分子使金属Co(Ⅱ)的配位数由6配位变成4配位,导致样品表面颜色由粉色向蓝紫色转变。在吸附实验中,样品仅对水分子具有较大的吸附能力,并且吸附水分子后样品的颜色恢复,由蓝紫色重新变回粉色。而在水分子传感研究中,发现MOF-2能对水分子产生典型的溶剂化显色效应,并且对水分子有高的灵敏性,其检测线可以低至10%以下。紫外-可见光谱解释了MOF-2对水分子产生溶剂化显示的机制:处于四面体环境中的Co(Ⅱ)会与吸附的水分子配位转变成八面体的几何构型,伴随着分裂能?0的升高,d电子跃迁所需要吸收的能量增大,因而波长逐渐向短波方向,相对应的MOF-2所呈现的颜色向长波方向移动,所以吸附水分子后,样品的颜色从较深的蓝紫色逐渐恢复到较淡的粉色,表现出较为明显的水分子显色效应。
[Abstract]:Material, the precursor and foundation of human material civilization, is the direct driving force for promoting social development and an important guarantee for the development of new energy and environmental pollution. It plays an important role in the long river of human history and is an indispensable part of human existence and life. Sensing materials, as a major "branch of functional materials" "Metal-organic frameworks (MOFs) has become a" tomorrow star "in sensing materials because of its rigid framework, permanent porosity, structural diversity, and simultaneous high chemical and thermal stability. Quantitative method, local surface plasmon resonance spectroscopy (LSPR), quartz crystal microbalance (QCM), surface acoustic wave sensing (SAW), micro cantilever Liang Chuangan (MCL), electrochemical impedance method, colloidal crystal (CC), etc. can satisfy the signal response to different molecules of the analyte, without fear of the properties of the MOFs material. And structure, great progress has been made in the field of organic small molecules, steam and gas, and anion / cation, and so on. In this paper, two new complexes are designed and prepared, and they are characterized by structure characterization, thermal stability analysis, water solvent sensing, adsorption properties, and the fluorescence lifetime of one of the luminescent complexes and quantum yield. The UV visible spectral spectra of the other complex with solvent color effect are studied as follows: 1,3,5- three benzoic acid ligands and amide ligands L1 and metal Zn (II) are prepared by self assembly through a mixed solvent heat method to prepare a single crystal junction of six square complexes with one dimensional spiral structure in the direction of B. The results show that there are two enantiomeric chiral structures in MOF-1, which crystallize in two space groups of P6422 and P6222 respectively, and each other for the external raceme.Platon and Topos software, the solvent occupancy of MOF-1 is 32.8% and it has a self insertion structure. Under the applied mechanical pressure, the samples of the original signal can be grinded by grinding. The fluorescence intensity, the fluorescence lifetime and the quantum yield are raised, and the water content in different organic solvents is analyzed. The results show that the samples after grinding can produce three different fluorescence response mechanisms to different concentrations. To the water molecules, the mechanism of the signal change of the emission wavelength with a red shift with the increase of concentration is shown. At a high concentration, the change mechanism of the fluorescence quenching with the concentration increases with the concentration of the water molecules. In addition, the adsorption properties of MOF-1 can be controlled by the water molecules to regulate the adsorption capacity of C2H2, C2H4, and CO2. Synthetic method, 4,4'- bipyridine and L2 ligand and metal Co (II) are prepared by self-assembly to prepare a case of water molecules to participate in coordination. The structure of MOF-2. single crystal structure of six party complex with one dimensional spiral structure shows that MOF-2 also has two enantiomeric chiral configurations, which crystallize in two space groups of P61 and P65, respectively. Under the vacuum heat treatment at 200 c, it is easy to lose the coordination water molecules to make the coordination number of metal Co (II) changed from 6 coordination to 4 coordination, which leads to the change of the color from pink to blue purple. In the adsorption experiment, the sample has a larger adsorption capacity for water molecules, and the color of the sample is restored after the adsorption of water molecules, and the color is changed from blue purple. In the water molecular sensing study, it is found that MOF-2 can produce a typical solvation effect on water molecules and have high sensitivity to water molecules, and the detection line can be as low as 10%. The UV visible spectrum explains the mechanism of MOF-2 to produce solvent display of water molecules: Co (II) in tetrahedral environment and adsorption The coordination of water molecules into the geometric configuration of the eight surface body, with the increase of the splitting energy 0, the energy absorbed by the d electron transition is increased, so the wavelength moves towards the short wave direction and the corresponding color of the corresponding MOF-2 moves towards the long wave direction, so the color of the sample is gradually recovered from the deeper blue purple to the lighter color after the adsorption of water molecules. The pink color shows a more obvious color effect of water molecules.

【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.4

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