【作者】 马德运；

【导师】 李映伟；

【作者基本信息】 华南理工大学 ， 应用化学， 2011， 博士

【摘要】 具有特殊性能或多功能的金属有机配位聚合物或金属有机骨架材料（MOFs）的研究与材料、物理、生命科学和化学等诸多研究领域密切相关。尤其是研究稀土配合物对于构筑结构新颖的拓扑网络和合成具有独特的光、电、磁、气体分离的新材料等方面具有重要的意义;此外,研究提高MOF材料的憎水性能是解决其工业应用的前提条件,因此具有重大的研究价值。依据晶体工程学原理,本文采用刚性的含氮杂环羧酸配体与过渡金属离子（4d）和稀土离子（4f）合成了一系列结构新颖的4f及4d-4f配位聚合物,探讨了它们的发光、吸附和传感等性能;此外,采用对苯二甲酸与4,4’-联吡啶/4,4’-联吡啶衍生物,在溶剂热条件下与过渡金属自组装成多个MOF新材料,深入探讨疏水基团的引入及其取代位置对MOF材料憎水性能的影响。论文的主要研究内容有:第1章介绍了本课题的研究背景,包括基于过渡金属离子、稀土离子或者稀土-过渡混合金属离子构筑的具有光、电、磁、吸附、分离、传感等性能的功能配位聚合物的研究现状和应用,并简要论述了本论文的选题依据。第2章探讨了水热条件下4-吡啶甲酸与反丁烯二酸发生原位脱羧和脱水配体耦合反应,并研究了通过原位配体反应生成的新配体构筑成二维配位聚合物的荧光性能。通过控制反应条件,采用浓硝酸作为氧化剂和酸性调节剂,在一定的温度和压力下,反丁烯二酸发生脱羧反应生成二氧化碳和3-羟基丙酸:二氧化碳进一步自身还原耦合生成草酸;3-羟基丙酸与质子化的4-吡啶甲酸通过脱水反应耦合生成3-（4-吡啶甲酸）丙酸。两组新配体与体系中的Eu³⁺离子进一步构筑成一个新的稀土配位聚合物,{[Eu（C₉H₈NO₄）（C₂O₄）]·2H₂O}n （1）,1由一维链Eu-oxalate和3-（4-吡啶甲酸）丙酸配体构筑而成,展现出二维层状结构,常温固态下在359 nm波长激发下发生特征的红色荧光,荧光衰减结果表明1的荧光寿命为368.5微秒。第3章描述了分别以2,6-吡啶二羧酸（H2pydc）和4-吡啶甲酸（HIN）为桥联配体合成了四个稀土-过渡混合金属配位聚合物,其组成分别为:[AgLn（pydc）₂（H₂O）3]·x（H₂O） [Ln = Eu, x = 1.25 （2）; Ln = Tb, x = 1.25 （3）],和LnAg（OX）（IN）₂·H₂O （Ln = Nd （4）; Eu （5））。荧光谱图结果表明含Eu和Tb的配合物在可见光区具有亮而窄的特征荧光发射,荧光衰减曲线表明,2、3和5的荧光寿命分别为431.8、886.8和756.6微秒。第4章在水热条件下,浓硝酸作为氧化剂和酸性调节剂,5-甲基-吡嗪-2-羧酸发生原位甲基氧化和脱羧耦合反应生成两种新配体:2,5-吡嗪二羧酸和草酸,与Eu³⁺离子进一步自组装成具有一维通道的三维微孔稀土金属有机配位聚合物[Eu₂（μ₂-pzdc）（μ₄-pzdc）（μ₂-ox）（H₂O）₄]·8H₂O （6）。研究结果发现,通过原位配体反应不但可以简化反应物原料,缩短反应时间,更重要是增大了晶体尺寸,提高了晶体纯度。配合物6中含有1D亲水孔道和动力学半径为2.1?大小的孔径,除去游离客体分子后的6a的荧光强度具有溶剂效应,对丙酮具有选择性识别,可用于荧光探针。第5章采用配体合成策略,在第二配体4,4’-联吡啶的2-和3-位上分别引入相同数量的疏水基团（甲基）后,与对苯二甲酸及过渡金属离子(Zn²⁺)在溶剂热条件下合成了两个含有1D通道的三维二重穿插MOF材料, [Zn₂（BDC）₂（P₂）]·（DMF）₂·（H₂O） （SCUTC-18）和[Zn₂（BDC）₂（P₃）]·（DMF）·（H₂O）₂ （SCUTC-19）。研究结果表明,与无疏水基团的有机配体构筑的MOF-508 [Zn₂（BDC）₂（P¹）]·（DMF）·（H₂O）₂]相比,疏水基团的引入能大大提高MOF材料的憎水性,而且,相同数量不同位置上的疏水基团对MOF材料憎水性能又有明显区别:疏水基团越靠近金属-羧基氧簇中心,憎水性能越强。此外,SCUTC-18对甲苯具有良好的吸附性能,可应用于除去室内有毒挥发性气体。更多还原

【Abstract】 Metal-organic coordination polymers or metal-organic frameworks（MOFs）, with unique property or multi-functionalities, have been closely related to materials, physics, life sciences and chemistry. The study of lanthanide-contained coordination polymers has important significance in the fields of constructing of intriguing topological nets and synthesizing new materials with unique luminescent, electronic, magnetic and gas separate. Moreover, improving the hydrophobic of MOFs is of great important to the realize industrial applications of MOF materials. According to the theory of molecular engineering, we have focused our study on the reactions of rigid azacyclo-carboxylic acid with lanthanide （4f）/transition （4d） metals. A series of novel coordination polymers containing the 4f or 4d-4f mixed metals were successfully synthesized. The unique luminescent, gas adsorption and sensing properties of these polymers were systematically studied. The main research works of this thesis are as follow:In chapter 1, the backgrounds of this study were briefly introduced, including the research progresses of 4d-, 4f- and 4d-4f-contained functional coordination polymers with unique luminescent, magnetic, electric, gas adsorption, separation and sensing propertyes. Finally, the research aims and contents of this thesis were proposed.In chapter 2, the in situ decarboxylation and dehydration coupling of fumaric acid and isonicotinic acid under hydrothermal conditions and the luminescent property of an unprecedented two-dimensional coordination polymer containing in situ formed new ligands, 3-（4-pyridinecarboxylate）propionic acid （inpro） and oxalate （ox） moieties were explored. Electrophilic addition of fumaric acid to form unstable 2-hydroxysuccinic acid, which could get decarboxylated with trace quantity of nitric acid under certain temperature and pressure to form CO₂ and 3-hydroxypropionic acid: the in situ reductive coupling of CO₂ generated oxalate anion; the condensation reaction between 3-hydroxypropionic acid and 4-carboxypyridinium moiety through dehydration led to the formation of the Hinpro acid which then coordinated with the Eu（III） ion along with the oxalate anion leading to the formation of the coordition polymer 1, {[Eu（C₉H₈NO₄）（C₂O₄）]·2H₂O}n. 1 displays a two-dimensional layered network constructed by Eu-oxalate chanins and inpor. Upon excitation at 359 nm 1 emited the red fluorescent and shown lifetimes of 368.5μs at room temperature.In chapter 3, four new 4d-4f coordination polymers based on 2,6-pyridinedicarboxylate or isonicotinic acid as bridging ligands were obtained, [AgLn（pydc）)₂（H₂O）3]·x（H₂O） [Ln = Eu, x = 1.25 （2）; Ln = Tb, x = 1.25 （3）],and LnAg（OX）（IN）₂·H₂O （Ln = Nd （4）; Eu （5））. The results shown that four 4d-4f coordination polymers emited characteristic fluorescence of lanthanide ions in UV-Visible （UV-Vis） region. The luminescent lifetimes of solid 2, 3 and 5 were measured to be 431.8, 886.8, and 756.6μs, respectively.In chapter 4, hydrothermal reaction of 5-methylpyrazine-2-carboxylic acid with trace amount of nitric acid as both oxidant and acidity modifier produced a novel microporous europium-conatining metal-organic framework [Eu2（μ2-pzdc）（μ4-pzdc）（μ2-ox）（H₂O）₄]·8H₂O （6）, which contained in situ oxidation of methyl and decarboxylation formed new ligands, 2,5-pyrazinedicarboxylate （H2pzdc） and oxalate （ox） moieties. It was found that in-situ synthesis of ligands from an organic precursor not only simplified the synthesis, but also led to enhanced crystal size and purity. 6 contained one hydrophilic channel within the three-dimensional structure and was able to host molecules with kinetic radii as big as 2.1 ?. The intensity of luminescence of guest-free MOF 6a exhibited solvent-dependent effects, which has the potential applications as a luminescent receptor for reversible and selective molecular sensing.In chapter 5, the self-assembly of terephthalic acid and 2,2’-dimethyl-4,4’-bipyridine/3,3’-dimethyl-4,4’-bipyridine with transition metal salt under solvothermal conditions obtained two new microporous metal-organic frameworks, [Zn₂（BDC）₂（P²）]·（DMF）₂·（H₂O） （SCUTC-18） and [Zn2（BDC）2（P3）]·（DMF）·（H₂O）2 （SCUTC-19）, which both featured the same three-dimensional coordination network with 1D open channles. The results indicated that the incorporation of methyl groups enhanced the stability of MOF-508 which constructed by 4,4’-bipyridine, terephthalic acid and Zn²⁺ under standard atmospheric conditions. Furthermore, the moisture stability of the MOFs depended strongly on the positions of the methyl substitutes on the 4,4’-bipyridine linkers. The hydrophobic groups closer to the Zn centers, the hydrophobicity of MOFs was stronger. The combination of high stability in air and hydrophobicity as well as high adsorption capacity for toluene implies that SCUTC-18 has potential capabilities for air-cleaning applications.更多还原