利用环戊烷羧酸和半刚性不对称羧酸构筑的配位聚合物合成、结构及性质研究

【作者】 崔林；

【导师】 王尧宇；

【作者基本信息】 西北大学 ， 无机化学， 2014， 博士

【摘要】 现如今,利用含有多配位点的有机配体与金属离子以自组装的方式合成了大量的多功能的配位聚合物(CPs),而这些配位聚合物所拥有的结构和性能很大程度上依赖于有机桥连配体的本性以及中心金属离子单元的特性。截至目前,由于构象丰富、配位点较多的原因,含有多个羧酸基团的环烷烃羧酸类配体已被大量的用来构筑配位聚合物,而这些配位聚合物已被证明在光学、磁学以及催化领域有着良好的应用前景。在本论文研究中,选取了拥有十种立体构象的环烷烃羧酸配体1,2,3,4-环戊烷四甲酸,为了研究在配位反应过程中1,2,3,4-环戊烷四甲酸的构象转换行为,选取了不同的金属离子以及不同的辅助配体,在水热条件下合成了四例新的“砖墙式”配位聚合物,并通过单晶X-射线衍射分析、傅里叶红外光谱分析(FTIR)、元素分析(EA)、热重分析(TGA)和粉末X-射线衍射分析(PXRD)将所合成配合物的结构进行了系统表征,并对配合物所拥有的性质(热稳定性、荧光特性以及分子磁性)做了详细的测试和深入的研究,并对环戊烷四甲酸在最终所合成出的配合物中所展示的构象和起始反应物所展示的构象进行比较,研究表明在利用构象丰富的有机配体在构筑配位聚合物过程中,温度对于构象转换起着决定性作用。除此之外,由于围绕中心非金属原子所发生的扭动,使得基于半刚性V形对称羧酸所构筑的配位聚合物的研究引起了大家越来越多的关注,而这些所构筑的配位聚合物被证明在荧光、磁性、催化以及吸附方面有着良好的特性。相比较V形半刚性对称羧酸,基于半刚性不对称羧酸的研究却相对较少。和半刚性对称羧酸相比,半刚性不对称羧酸同样因为中心非金属原子的原因会发生一定的扭转,而且由于其围绕中心非金属原子的两部分基团的不对称,使得合成出来的结构呈现出不可预知性。截至目前为止,利用此类半刚性不对称羧酸配体所构筑的配位聚合物已被证明拥有迷人的结构和良好的荧光、磁学性能等特性。在本论文的后续研究中,选取了两例含有O为中心非金属原子的半刚性不对称羧酸配体3-(4’-羧基苯氧基)邻苯二甲酸(4-H3cpta)和3-(3’-羧基苯氧基)邻苯二甲酸(3-H3cpta)作为研究对象。为进一步研究这两类半刚性不对称羧酸配体的配位行为以及在组装配合物的过程中各影响因素分别对不同方面的影响,分两部分对其配位行为进行研究：a)同时利用两个半刚性不对称羧酸作为第一配体,并选取了不同类型的含氮配体,比如柱状的桥连含氮配体或封端配体等作为第二配体,在不同金属参与组装条件下,合成了六例结构多样的配位聚合物：{Cd3(2,2’-bpy)2(3-cpta)2·H20}n(5)、{Cd(bpa)0.5(3-cpta)·[NH2(CH3)2]}n(6)、{Mn3(2,2’-bpy)2(3-cpta)2·H20}n(7)、{Mn(bpa)0.5(3-cpta)(H2O)2·2H20}n(8)、{Zn3(1,10-phen)2(3-cpta)2(H20)2·2H20}n(9)和{Zn3(dpa)2(4-cpta)2}(10)。所合成的配位聚合物具有不同的空间维数、拓扑结构以及性能,其中配合物5和7为首例基于此类配体所合成的手性层状结构；配合物6主体框架为一个二维的阴离子框架结构,通过晶格中的二甲胺阳离子将电荷中和,使得整体框架显示电中性；配合物8在与配合物6选取同种有机配体和反应溶剂条件下,却展示了一个三维的框架结构；配合物9和配合物10,在所选取的第二配体为同种类型的前提下,仅是所选取第一配体中羧酸基团的位置不同,就使的配合物的空间维数发生比较大的变化。研究结果表明,金属离子、溶剂和取代基位置对于基于此类配体的配位聚合物的构筑有重要的影响。对配合物中5、6、9和10的荧光性质做了研究,此外对配合物7和8的磁学性质也进行了研究。b)为了进一步研究在构筑配位聚合物过程中影响因素所影响的方面,在合成体系中选取3-(4’-羧基苯氧基)邻苯二甲酸(4-H3cpta)与Co(Ⅱ)离子和bpe/bpa在水热/溶剂热条件下合成了一系列新的配位聚合物11-13：{Co3(cpta)2(bpe)3(H20)4}n(11)、{Co2(μ2-H2O)(μ3-OH)(Hcpta)(bpe)(H20)·3(DMF)3(H20)}n(12)和{Co3(cpta)2(bpa)4}n(13)。从单晶结构研究上来看,溶剂对于配位聚合物的框架结构起着尤为重要的作用；从最终配位聚合物所展示的性质来讲,第二配体对于配合物的性质影响较大。此外,配合物12中分子与客体分子之间的超分子作用力(氢键作用力和van der Waals作用力)以及分子之间的相互作用力(氢键作用力和π-π作用)对稳定框架结构、增强配合物晶体结构和形成三维超分子网络起着非常重要的作用。同时对配合物11-13的磁学性能进行了研究。更多还原

【Abstract】 Nowadays, a great deal of coordination polymers based on multitopic organic spacers and metal ions have been self-assemblied. And the structures and properties possessed mainly depend on the natures of the organic bridging ligands and metal centers. Because of abundant conformations and more coordination topics, many coordination polymers based on cycloalkylcarboxylic acids with multi carboxylate groups have been synthesized up to now, which are proven having excellent properties in molecular optics, magnetism and catalysis. In the beginning of this dissertation, cyclopentanetetracarboxylic acid (cis,cis,cis,cis-1,2,3,4-cyclopentanetetracarboxylic acid) has been chosen as researching object. In order to investigate the conformation-transfer behaviors, four new "brick-wall"-shaped coordination polymers have been hydrothermal synthesized, which are structural characterized by Single-Crystal X-Ray Diffraction analyses, Fourier Transform Infrared Sppectroscopy (FTIR), Elemental Analyses (EA), Thermogravimetric Analysis (TGA) and Powder X-Ray Diffraction analyses (PXRD). Besides, the properties are also studied (for example, thermostabilities, fluorescence characteristic and magnetism). The conformation of the cyclopentanetetracarboxylate ligand in the initial reactant and the final coordination polymers are also investigated. The result shows that the temperature plays the most important role during the conformation-transfer when constructing coordination polymers with organic ligands of various conformations.In addition to that mentioned above, coordination polymers with V-shaped semi-rigid symmetry carboxylate ligands have attracted quite attentions because the backbone of the spacers could twist around the center non-metallic atoms, which are proven to have many excellent properties in luminescence, magnetism, catalysis and absorption. Compared to the symmetry ones, the reports about complexes based upon Ⅴ-shaped semi-rigid asymmetry ligands are a little rare, probably because the asymmetry characters of the backbones, which make the final structures unpredictable. Coordination polymers constructed with the semi-rigid asymmetry carboxylate ligands have been proven to have charming architectures and excellent luminescence and magnetic properties. In the following researches of this thesis, two semi-rigid asymmetry carboxylate ligands with oxygen atom as the center non-metallic atoms,3-(3’-carboxyphenoxy)phthalic acid (3-H3cpta) and3-(4’-carboxyphenoxy)phthalic acid (4-H3cpta) are chosen to constructed coordination polymers. The coordinated behaviors and the influence factors during the assembling CPs are also studied in the further researches: 1. Two semi-rigid asymmetric carboxylic acids are used as the main ligands at the same time, and different types of N-donor ligands are also chosen, such as pillar-bridge linked N-donor ligands and chelate ligands as the auxiliary ligands. After assembling with different metals, six coordination polymers with diverse structures were synthesized, which have different dimensionalities, topological structures and properties:{Cd3(2,2’-bpy)2(3-cpta)2·H2O}n (5)、{Cd(bpa)0.5(3-cpta)·[NH2(CH3)2]}n (6)、{Mn3(2,2’-bpy)2(3-cpta)2·H2O}n (7)、{Mn(bpa)0.5(3-cpta)(H2O)2·2H2O}n (8)、{Zn3(1,10-phen)2(3-cpta)2(H2O)2·2H2O}n(9)和{Zn3(dpa)2(4-cpta)2}(10). Complex5and7are the fist type of chiral layer structure with this type ligands; Complex6is a anionic2D layer structure, which is neutralized by the lattice dimethylamine cation; Complex8and Complex6are synthesized under the same reaction condition but different metal salts, different from Complex6, Complex8is a3D framework. Complex9and10are synthesized with the same auxiliary ligand and solvent but different carboxylate position, which make the final structures quite different. The result of the research shows that solvents, metal ions and positions of the substituents all have the important influences on the CPs with this type organic ligand. Besides, the luminescence properties of Complex5,6,9,10and magnetic properties of Complex7and8are also studied.2. In order to study the influence factors during the process of coordination polymers construction aspects,3-(4’-carboxyphenoxy)phthalic acid (4-H3cpta) and Co(II) ion are synthesized with bpe/bpa under hydro/solvothermal reactions, and three new coordination polymers11-13are obtained:{Co3(cpta)2(bpe)3(H2O)4}n (11){Co2(μ2-H2O)(μ3-OH)(Hcpta)(bpe)(H2O)·3(DMF)3(H2O)}n (12)和{Co3(cpta)2(bpa)4}n (13). After the study about the structures of the single crystals, it is shown that solvents play the main effect to the final structures. While the natures of the auxiliary ligands play the important role on the final properties of the complexes. In addition, the supermolecular forces between framework and guest molecules in Complex12(hydrogen bonds and van der waals force) and interaction forces between molecules make the whole structure more stable. The magnetic properties among the three complexes are also studied.更多还原