【作者】 马惠卿；

【导师】 孙道峰；

【作者基本信息】 山东大学 ， 无机化学， 2014， 博士

【摘要】 金属-有机框架物(Metal-Organic Frameworks,MOFs),又名金属-有机配位聚合物,是一类利用金属离子的几何配位构型与有机配体的配位能力,借助于共价键或离子键相互联接构筑的具有规则周期性网络结构或孔道结构的晶态材料。有机配体是构筑金属-有机框架物的主要组分,其常见的合成方法主要分为以下两种：一是原位合成,另一个是传统的有机合成。前者通常是在“一锅”反应条件下进行的,是指前躯物原位转化成有机配体后,直接与金属离子桥联形成配位聚合物。原位反应一般会涉及水解,脱羧,烷基取代,羟基化等多种反应。传统的有机合成主要是指前驱物通过一步一步的有机反应得到目标配体,然后将合成的有机配体用于MOF材料的自组装。由于有机配体对金属-有机框架物的最终结构有着重要的影响。本论文设计合成了一系列不同结构的大骨架芳香性羧酸类配体(H3L3, H3L4, L5, H2L6, H2L7, L8,H4L9,H4L10)M通过配位键与金属离子Zn2+,Cd2+和Cu2+组装合成了8个具有新颖结构的金属-有机框架物,并通过X-射线单晶衍射、元素分析、热重分析、X射线粉末衍射、荧光分析和气体吸附等对它们进行了结构表征和性能测试。本论文的主要内容如下：一、利用含氰基配体L,通过原位反应得到了配合物1,2,3,在1和2中,前躯体L中氰基通过原位反应生成四唑型配体L2并参与配位,而在配合物3中由于盐酸的加入导致L的氰基水解成羧基参与配位。通过对三种配合物结构分析,我们发现最终导致配合物1和2结构相异的原因主要是配体采取了不同的配位模式：在配合物1中,采取顺-顺配位模式的部分L2配体将单核的SBU连接构筑成双核的分子结构,然后通过顺-反配位的配体将双核的分子结构扩展成一个二维层状结构；在配合物2中由于配体L2只采取了双齿螯合的一种配位模式,从而将-0轴向的两个配位点留给了可参与配位的溶剂水分子,阻止了进一步在空间上的延伸,形成了零维结构。配合物1的层与层之间存在着强烈的氢键作用,将二维层连接形成了三维超分子结构；而在2中,氢键发生在配位的水分子和四唑N原子间,零维的分子簇沿a,b两个方向延伸形成结构稳定的二维层状超分子结构。二、配合物6具有自穿插的拓扑结构,结构中的最小回路是12元环。这些最小回路相互交织穿插在一起形成一个完整的三维网络拓扑结构。由于结构中所有的边具有相同的属性,因此不能通过破坏某一个化学键,将整体结构拆分成全新的独立的二维格子或者三维网。这一点不同于以往报道的具有自穿插结构的MOF,我们称之为强自穿插。配合物6具有较高的拓扑密度,TD10=3245；由RSCR数据库可知配合物6是目前已知的最高拓扑密度的(3,4)-连接的自穿插网络结构。三、我们合成了五个基于硅烷结构的配体(配体3,4,6-8),并利用这5个有机配体与金属离子自组装合成了五个具有新颖结构的金属-有机框架物。其中配合物4和5是利用相同的金属离子和有机配体在不同溶剂中自组装形成的两个不同结构的配合物。配合物4是一个二重穿插的结构,而配合物5是一个笼状结构。配合物7和8由于选择不同长度的有机配体使得结构从非穿插的变为二维穿插的微孔框架物。更多还原

【Abstract】 Metal-organic frameworks (MOFs), also known as coordination polymers, are crystalline coordination-based compounds in which metal centres are bridged via organic multitopic ligands to form multi-dimensional networks. The synthesis of MOF always begins with selection of the two maininteracting components-:the metal centres or the metal clusters and the bridging organic ligands. Nowdays, non-conventional in situ synthesis and conventional organic synthesis are the common ways of designing and preparing organic ligands. In the former ligand precursors are modified in situ to give organic ligands which are subsequently linked to the metal centres. This procedure may involve hydroxylation, decarboxylation, alkylation and hydrolysis, among others. In conventional synthesis the organic ligands are prepared, step-by-step, from organic precursors and the resulting compounds are later employed in the self-assembly of MOFs.After theoretical study on the influence of the ligand on the synthesis of metal-organic frameworks, we designed and synthesized a series of nonplanar aromatic multi-carboxylate ligands with a big rigid structure (H3L3, H3L4, L5, H2L6, H2L7, L8, H4L9, H4L10). Eight novel MOFs were obtained through the assembly reactions between the synthesized ligands and Zn2+, Cd2+, Cu2+. All complexes have been characterized by single-crystal X-ray diffraction, elemental analysis, thermal analysis, XPRD analysis, fluorescence spectroscopy, and gas adsorption. The contents of this dissertation are as follows:1. Three new metal organic coordination compounds,[Cd (L2)2]·4.5H2O (1),[Zn(L2)2·(H2O)2]·0.5H2O (2) and Cu(L1)2(3),(L2=3-chloro-2-(5H-tetrazol-5-yl)pyridine; L1=3-chloropicolinic acid), have been hydrothermally synthesized, in which, L2and HL1were synthesized via in situ reaction. MOF-(1-3) shows diverse structures by changing from a zero-dimensional cluster to1D chain to2D44layer. The changes in structure result from the different bridging abilities of tetrazolate ligands. Weak interactions, such as hydrogen bonds and halogen bonds, play important role in the construction of metal-organic frameworks.In addition, three complexes display modest thermal stability and compound1and2show strong solid-state fluorescent emissions.2. A3D (12)4(12)3coordination network with high topological density and extremely tight self-catenation of12-rings has been obtained based on [Cu2(COO)4] paddlewheel SBUs and a tripodal carboxylate linker. The self-catenation is " strong" i.e., the network cannot be transformed into an array of interpenetrating nets by breaking any chemical bond. To the best of our knowledge, MOF-6has the highest topological density among all known3,4-coordinated nets.4. Five different silicon-based ligands have been designed and synthesized. We synthesize and characterize five different novel metal-organic frameworks. The solvent system plays an important role in modulating the final structures. Complex5and8present3D double-interpenetrating network. Complexes4and7show the noninterpenetrated frameworks.更多还原