【作者】 王锋；

【导师】 李东风；

【作者基本信息】 华中师范大学 ， 有机化学， 2012， 博士

【摘要】 本文主要研究了基于芳香羧酸构筑的金属-有机框架(MOFs)及其杂化材料的合成、结构与性能：1.利用水热和溶剂热反应合成了16个基于芳香多羧酸构筑的MOFs,研究了这些化合物的合成、结构与性能。通过筛选,化合物[Cd (2,2’,4,4’-bptcH2)](F-3)可做为高效的有机磷酸酯农药(OPs)的固相萃取吸附剂,结合溶出伏安法检测痕量的OPs。实验中以甲基对硫磷(MP)为模型化合物,当MP的浓度范围在0.01到0.5μg·mL-1时,特定的峰位电流与MP的浓度成正比,其检测限可以达到0.006mg·mL-1,10次重复率偏差为5.2%。检测对应的硝基苯和含氧无机阴离子(PO43-, SO42-, NO3-)没有明显的干扰现象,该实验是第一例使用MOFs作为固相萃取剂修饰电极结合溶出伏安法检测OPs化合物的成功尝试。合成了基于镧系离子为基础的MOFs,发现这类具有荧光功能的MOFs可以在硝基苯及其衍生物等有毒害分子检测方面得到应用;硝基苯及其衍生物对化合物[Eu3(TCSi)2(NO3)(DMF)3(H2O)-Solvents]n(F-12)不[Tb3(TCSi)2(NO3)(DMF)3H2O)·Solvents]n(F-14)的荧光有明显的淬灭作用,淬灭效率都超过92%；结果表明,化合物F-12和F-14可用作硝基苯及其衍生物的传感。2.成功合成了一种新的多功能无机-有机杂化材料SWNT-Zn。该材料的合成方法是利用苯甲酸共价功能化的单壁碳纳米管(SWNTs)作为有机连接体,以Zn2+离子为节点,通过溶剂热的方式合成的类似多孔金属-有机框架的新材料。新材料具有两个明显的优点,一是它的多孔性,可用于气体的储存与分离,还有利于吸附其它介质；二是它内在的电子传导性,可在电化学方面得到应用。SWNT-Zn的比表面积为1210m2g-1比原始SWNTs的比表面积儿乎增大一倍。SWNT-Zn的高压氢气质量吸附在12bar时达到最大3.1wt%,比SWNTs的高压(12bar)氢气质量吸附量1.2wt%要高近3倍。合成该类材料的方式可以推广用于基于碳纳米管/MOFs复合新材料合成。3.采用环境友好的方式,通过在水/乙醇相中利用共沉淀法合成了镧系离子与均三苯甲酸构筑的系列纳米晶态金属-有机框架(NMOFs),并通过物理和化学方法表征证实了NMOFs的组成结构为Ln(BTC)(H2O)6。改变不同反应方式可以改变产物的形貌,通过改变反应时间、温度、反应物浓度、溶剂等方式获得不同环境下合成的NMOFs,考察了不同环境下生长的NMOFs在荧光性能上的变化,并证实了该类NMOFs的配位导向自组装的形成机理。选取Eu3+和Tb3+离子与均三苯甲酸合成的NMOFs可用于硝基苯及其衍生物的荧光检测,其中分析试剂4-硝基甲苯对该两类NMOFs的荧光淬灭效率分别高达94.26%和82.28%。同样采用共沉淀的方法,利用2-氨基对苯二甲酸的甲胺盐与Eu3+和Tb3+离子在水相中反应,获得相应的NMOFs,其中分析试剂4-硝基苯对含Eu3+离子产物的荧光淬灭效率也高达92.41%,而对含Tb3+离子产物的荧光淬灭效率只有57.75%。将镧系离子的反应延伸到其它过渡金属,选用Zn2+和Cd2+分别与2-氨基对苯二甲酸的甲胺盐在水相中反应,获得相应的NMOFs,分析试剂2-硝基苯对该两种NMOFs的荧光淬灭效率也分别达到89%和81.31%。比较硝基苯及其衍生物对合成NMOFs的荧光淬灭效率可以更好寻求对该类物质优异的传感器。发展的水相共沉淀法形成NMOFs的方法可以广泛地应用在由芳香羧酸与常见金属离子构筑的NMOFs合成中,该方式还可以放大合成,为发展NMOFs的工业应用奠定了基础。更多还原

【Abstract】 The syntheses, structures and properties of metal-organic frameworks (MOFs) and their hybrid materials based on aromatic carboxylic acids ligands were studied in this dissertation.1. Sixteen metal-organic frameworks were synthesized by hydrothermal and solvothermal reactions, and the syntheses, structures and properties of these compounds were studied. In these compounds,[Cd (2,2’,4,4’-bptcH2)](F-3), behaving strong adsorption ability, could be used as sorbents for solid-phase extraction (SPE) of organophosphate compunds(OPs) and their detection. Methyl parathion (MP) was selected as a model to demonstrate the effectiveness of F-3for detecting of electroactive OPs compounds. Therefore, the stripping voltammetric performances of MP absorbed on the surface of F-3were evaluated by square-wave voltammetric (SWV) analysis. Well-defined peaks, proportional to the concentration of the corresponding MP, were observed in the range from0.01to0.5μg·mL-1. A detection limit of0.006mg-mL-1was obtained and the relative standard deviation was5.2%for10replicate determinations. Furthermore, no obvious interferences were observed from the electroactive derivatives such as nitrobenzene, and other oxygen-containing inorganic ions (PO43-, SO42-, NO3-) with the peak currents of MP varied slightly. To the best of our knowledge, this is the first successful attempt on the determination of OPs by using MOFs as SPE based on SWV method. Several lanthanides-based metal-organic frameworks were also synthsized. We found that nitroaromatics copounds act as flourescence quenchers for compounds [Eu3(TCSi)2(NO3)(DMF)3(H20)-Solvents]n (F-12) and [Tb3(TCSi)2(NO3)(DMF)3(H2O)·Solvents]n (F-14). The results showed that all the quenching efficiency is more than92%, and compounds F-12and F-14can selectively detect nitroaromatics compounds. It is to be expected that this work will stimulate extensive research on the detection of some pollutants by MOFs with fluorescence.2. Single-walled carbon nanotubes (SWNTs) covalently functionalized with benzoic acid (SWNT-PhCOOH) can be integrated with transition metals ions (Zn2+) to form three-dimensional porous inorganic-organic hybrid frameworks (SWNT-Zn). Compared to metal-organic frameworks (MOFs), SWNT-PhCOOH and Zn2+can be regarded as organic linker and node, respectively, resulting in high dimensional MOFs-like porous materials. The resulted inorganic-organic hybrid material is expected to exhibit enhanced specific surface area with a mass of open metal sites to give a better gas adsorption capacity. The BET surface area of SWNT-Zn is1210m2g-1, which is about2time to SWNTs. SWNT-Zn also reveals that the excess H2uptake maximum reaches about3.1wt%(12bar), which shows almost three times compared to the original SWNTs(1.2wt%at12bar). The present synthetic strategy can be extended to the preparation of other new hybrid materials based on SWNTs/MOFs for applications in a wide range of areas.3. The treatment of lanthanide ions with1,3,5-benzenetricarboxylic acid (H3BTC) in a water-ethanol solution facilely yields nanocrystal lanthanide-based metal-organic frameworks (NMOFs). The structures and the molecular formula Ln(BTC)(H2O)6of the as-synthesized samples were confirmed by various physical and chemical means. Influence of different synthesis parameters on the morphologies, such as the concentration and molar ration of the reactants, reaction temperature, reaction time and solvents, and photoluminescence of the as-synthesized samples at different condition were investigated. A coordination-induced assembly growth mechanism was confirmed to the samples. We found that4-nitrotoluene act as fluorescence quenchers for the Eu-and Tb-containing samples, and the quenching efficiency is94.26%and82.28%, respectively. The coprecipitation reactions between the Eu3+/Tb3+ions and the methyl ammonium salts of2-aminoterephthalic acid in a water phase yield NMOFs samples. The fluorescence of samples are quenched by4-nitrotoluene and the quenching efficiency is92.4%and57.75%, respectively. In additional, the coprecipitation reactions in a water phase were also carried out between Zn2+/Cd2+and the methyl ammonium salts of2-aminoterephthalic acid obtaining NMOFs. Used the fluorescence quencher analytical reagent2-nitrotoluene, the quenching efficiency for Zn-and Cd-containing samples is89%and81.3%, respectively. The contrast nitrobenzene and its derivatives on the fluorescence quenching efficiency of the as-synthesized NMOFs can be better to seek more excellent sensors. The coprecipitation synthesis method in a water phase for NMOFs can be widely used in more NMOFs constructed by aromatic carboxylic acids and metal ions, and this method can be used to the large-scale synthesis of structure-defined NMOFs for industrial purposes.更多还原