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题名	基于多膦酸和多羧酸配体的金属有机骨架材料的合成和性质研究
作者	吕晓霞
学位类别	博士
答辩日期	2013-11
授予单位	中国科学院研究生院
授予地点	北京
导师	赵学波
关键词	金属有机骨架材料 V-型双膦酸配体 双亚氨基二乙酸配体 柔性三羧酸配体 苯并咪唑羧酸配体 荧光 磁性 气体吸附
学位专业	化学工程
中文摘要	金属有机骨架化合物（MOFs）具有丰富的拓扑结构，较高的比表面积，而且其结构和性质可根据具体的应用进行调节。因此，MOFs材料自诞生之日起就引起国内外研究者的广泛关注。MOFs是由有机配体与金属离子通过自组装过程形成的具有周期性网络结构的晶体材料，配体的设计和选择无疑会对其结构和性质产生重要的影响。尽管人们在晶体工程思想的指导下，合成了许多结构新颖、性能优良的金属有机框架材料，然而，开发具有不同配位基团和几何构型的新型有机配体依然是合成具有特殊结构和性能的MOFs材料的策略之一。本论文在合成几种新型有机配体的基础上，系统地探索和研究了配位官能团、配体的几何构型和反应条件对金属有机骨架结构的影响以及具有不同结构的骨架材料所具有的性质。 首先，设计合成了V-型双膦酸配体H4L1，利用该配体和4,4΄-联吡啶或1,2,4 -三氮唑辅助配体得到了二维层状化合物1和2、具有三核镍簇的一维链状化合物3以及由π-π作用形成的具有一维孔道（12.1×7.3 Å2）的三维网络化合物4。化合物3的磁性测试结果表明该化合物具有一定的反铁磁性。化合物4的气体吸附结果表明其对CO2、CH4、N2、O2以及H2均具有一定的吸附，且H2吸附曲线呈现阶梯形，脱附曲线表现出一定的滞后。该化合物上77 K条件下的H2的模拟计算结果表明模拟计算的曲线具有与实验值相同的变化趋势，但其值要高于实验值。另外，该化合物在低温低压下 N2和O2的吸附也表现出一定的特异性：压力小于4 bar时，N2的吸附量要高于O2。 其次，设计合成了双亚氨基二乙酸配体H4L2，并在水热条件下得到了两种同构的金属有机骨架结构 5和 6。在该结构中，金属与羧基形成了无限的一维纳米管（直径5.1 Å）二级结构单元，每个纳米管都通过配体与其他六个相同的纳米管相连，形成具有另一个一维三角形孔道（8.4×8.4×8.4Å3）的fnh型三维拓扑网络。热重分析结果显示这两个化合物均可以在350 ℃下保持稳定。活化去除溶剂后的粉末XRD分析显示脱除溶剂分子后这两个化合物依然保持原有框架结构。气体吸附结果显示它们对N2、H2、CO2和CH4均具有一定的吸附性质，77 K下N2吸附表征的化合物5的孔体积与PLATON计算的值一致。化合物5的吸附量高于化合物6 ，但二者的CO2零表面吸附焓均为24.6 kJ/mol。     第三，利用三角形的柔性三羧酸配体H3L3与硝酸锌在不同溶剂中形成了一维链状的化合物7和二维层状的化合物8。而用该配体与硝酸钴在不同反应温度和反应物配比的条件下，生成了两种不同的二维层状化合物10和11。用该配体与硝酸镉得到了与化合物7类似的一维链状化合物9。另外，这几种化合物均在π-π或氢键的作用下形成了具有一维孔道的三维网络。荧光分析显示化合物7,8,9均具有一定的发光性质。而磁性表征的结果显示化合物11具有一定的反铁磁性。 最后，利用苯并咪唑羧酸配体H3L4与硝酸锌合成了具有左手螺旋一维矩形孔道（10.7×20.6 Å2）的三维SrSi2型网络化合物12，该化合物表现出一定的荧光性质。气体吸附测试结果则显示：77 K时该化合物对N2和H2都几乎没有吸附，但是当温度升到195 K时，N2却有了明显的吸附，吸附量随压力升高呈现阶梯状变化，且脱附曲线明显滞后于吸附曲线，同样的195 K下CO2的脱附曲线也滞后于吸附曲线，表现出明显的“呼吸效应”。 本论文中不仅合成了三种不同的新型配体，还利用不同的配体得到了一系列包括由π-π、氢键等弱作用形成的三维网络结构在内的新颖金属有机骨架材料，丰富了配体的种类和配合物的结构类型。本研究最主要的创新之处在于首次合成了由无限金属羧基纳米管二级结构单元构筑的MOFs材料，这对于同类化合物的设计合成具有一定的指导意义。另外，由化合物5和12活化后的XRD谱图可知，在一定条件下柔性配体可以形成刚性骨架，而刚性配体也可以形成柔性结构。这些研究对于晶体工程的实践以及设计和合成具有特定功能的MOFs材料有一定的理论价值。
英文摘要	Metal organic frameworks (MOFs) have aroused widespread attention due to its diversities of topological structures and high surface area. Moreover the structure and properties of MOFs can be tailored based on the specific application. It is well known that MOFs are organic-inorganic hybrid materials with periodic network structure of crystals constructed from the assembly of the organic ligands with metal ions or clusters. The design and selection of ligands can undoubtedly affect their structures and properties. Although many MOFs with impressing structure and excellent performance have been synthesized on the basis of the principle of crystal engineering, the exploiting of novel organic ligands with different steric configurations and coordinated functional groups is still one of the effecitve strategies to construct MOFs with special structure and properties. In this paper, three novel ligands were synthesized, and base upon them, the studies about the effects of coordination groups, ligand configuration and reactions conditions on MOFs’ structure and properties were carried out. Firstly, a V-shaped diphosphonate ligand H4L1 was synthesized and four compounds (1-4) were formed by the reaction of H4L1 with metal ions in the presence of auxiliary 4,4΄-bipydine or 1,2,4-1H-triazole. Compounds 1 and 2 exhibit square-grid layer and bilayer 2D networks, respectively, while compound 3 is 1D chain fromed by trinuclear Ni cluster and compound 4 shows a 3D network with 1D channels (12.1×7.3 Å2) based on π-π interactions. Magnetic study reaveals that compound 3 exhibites an antifeerromagnetic behavior. Gas sorption measurements performed on compound 4 reveals permanent prosity after removing the guest molecules and shows moderate uptakes for CO2, CH4, N2, O2 and H2. Additionally, H2 isotherms on this coordination polymer exhibits interesting stepwise and hysteric adsorption behaviors. The results of molecular simulation show that the simulation curve had the same trend with the experimental curve of H2 at 77 K, but its value was higher than the experimental one. An unusual phenomenon was also observed that the uptake of N2 was higher than the uptake of O2 under the same conditions, which has not ever been observed in common porous materials yet. Secondly, A multi-iminodiacetic ligand H4L2 was synthesized and two isomorphic compounds 5 and 6 were formed through the solvothermal reaction of this ligand with Co(II) and Ni(II) salts. In this structure, the metal ions and carboxyl groups forms a infinite 1D nanotube (diamerter 5.1 Å), which could be served as second building unit (SBU). This nanotube is mutually connected by linker, resulting in a 3D fnh-type netowork with another 1D triangle tubular channels (8.4×8.4×8.4 Å3). Both of the two compounds are thermally stable up to 350 °C. The gas sorption measurements on them reveal moderate uptakes on CO2, CH4, N2 and H2. In addition, although these two isostructural compounds have different CO2 uptakes, the CO2 zero surface enthalpy for both of them are 24.6 kJ/mol. Thirdly, five novel MOFs (compounds 7-11) were constructed by using a triangular flexible tricarboxylate ligand H3L3. Compounds 7 and 8 were formed by the reaction of H3L3 and Zn(NO3)2·6H2O in different solvents and they exhibit 1D chain and 2D layer, respectively. Compounds 10 and 11 with different 2D layered structures were constructed by using this ligand and Co(NO3)2·6H2O under different solvothermal conditions. The compound 9 was generated by employing this ligand and Cd(NO3)2·4H2O in the same method as compound 7 and shows 1D chained structure too. All of these coordination polymers form 3D networks with 1D channels through π-π interactions or hydrogen bonding. Fluorescence analysis reveals that the compounds 7, 8 and 9 exhibit luminescent properties. And the magnetic study shows that the compound 10 shows an antifeerromagnetic behavior. Finally, a benzimidazole-carboxylate ligand (H3L4) was syntehsized and a 3D SrSi2-type network 12 with a 1D L-helical rectangular channel (10.7×20.6 Å2) was obtained based on this ligand. Luminescent properties was observed on this compound. Gas sorption studies show that the compound shows almost no adsorption for N2 and H2 at 77 K. However, when the temperture raise to 195 K, it shows a larger uptakes for N2 and an interesting stepwise N2 adsorption-desorption isotherm, which exhibits obvious hysteric loops. A hysteric isotherm is also observed for CO2 adsorption at 195 K, indicating an obvious structural breathing effect. In this paper, we not only sythesized three novel ligands with different coordinated groups and different configuration, but also obtained a series of MOFs with intriguing structures, including the 3D networks constructed from hydrogen bonding and π-π interactions.These works enrich the family of the ligands and MOFs. The main innovation of this work is that a novel secondary building uint constructed from metal-carboxylate nanotube is presented here for the first time. In addition, a conclusion can be drew from the experimental results that the flexible network can be obtaind from rigid ligand and the rigand network also can be synthesized from flexible ligand. All of these would provide some guiduance for designing and constructing functionalized MOFs for spcific purpose.
语种	中文
学科主题	储氢及新型纳孔材料
公开日期	2014-04-03
内容类型	学位论文
源URL	[http://ir.qibebt.ac.cn:8080/handle/337004/1767]
专题	青岛生物能源与过程研究所_储氢及新型纳孔材料团队
推荐引用方式 GB/T 7714	吕晓霞. 基于多膦酸和多羧酸配体的金属有机骨架材料的合成和性质研究[D]. 北京. 中国科学院研究生院. 2013.

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