【作者】 谷晓俊；

【导师】 薛冬峰；

【作者基本信息】 大连理工大学 ， 化学工艺， 2008， 博士

【摘要】 鉴于晶体在基础和应用研究领域的重要性,人们开始采取分子设计手段去探索各种新型晶体材料。晶体工程涉及分子或化学基团在晶体中的行为、晶体的设计、结构和性能的控制以及晶体结构的预测等,是实现从分子到材料的一条重要途径。金属-有机配位聚合物是将晶体工程引入到设计新颖的超分子结构并控制其功能和性质方面最成功的范例。相对于由过渡金属或稀土离子与有机配体构筑的单一金属配位聚合物而言,稀土-过渡异金属配位聚合物的研究还比较滞后。不同化学行为的过渡金属离子和稀土离子在复杂的化学环境中通常表现出弱的选择性,这使得两种不同属性的金属离子与有机配体的竞争反应常常导致产物中仅含有一种金属离子。如何选择和设计合适的构筑单元,并通过特定组装来获得具有预期结构与功能的稀土-过渡异金属配位聚合物成为当今化学和晶体学领域的一个挑战。本论文运用晶体工程原理,提出了表面修饰策略、异金属构筑单元维度提升策略和配体导向组装策略,开展了新型稀土-过渡金属配位聚合物的结构、性能以及组装规律的研究。具体工作如下:一、选用3-氨基-1,2,4-三氮唑-5-羧酸、3,4-吡啶二羧酸、对苯二甲酸、异烟酸和硝酸为配体,研究了九个过渡金属和稀土配位聚合物。(1)以含羧基的有机化合物为桥连配体,合成了两个单一锌配位聚合物、两个Zn-Cu配位聚合物和两个单一稀土配位聚合物。具有三维结构的两个Zn-Cu配位聚合物,一个实现了二维锌-氧层和一维铜-碘链的构筑,另一个实现了Zn-Cu-有机层的构筑。(2)以硝酸根为表面修饰配体,构筑了目前最大的二十六核稀土聚集体。并以此为构筑单元,组装了两个超大的四聚体。其中,由二十六核镝和四核镝构筑的四聚体具有慢的磁弛豫行为。二、选取异烟酸为桥连配体、含羧基的有机化合物为辅助配体,研究了九个手性或非手性Ln-Ag异金属配位聚合物。(1)利用银离子诱导产生的一维无机螺旋链为手性单元,稀土离子和银离子与非手性异烟酸之间的配位键为手性相互作用,构筑了两个手性异金属配位聚合物。(2)通过调控桥连配体和辅助配体的种类,得到了七个由一维无机异金属链或稀土-羧酸单元构筑的非手性异金属配位聚合物。研究表明,利用维度提升策略所构筑的含有一维无机异金属链的配位聚合物具有定向组装性和较高热稳定性。三、选用具有导向功能的异烟酸为桥连配体、含羧基或磺酸基的有机化合物为辅助配体,以不同构型的铜-碘聚集体和稀土-氧聚集体(或稀土-羧酸聚集体)为构筑单元,研究了二十六个手性或非手性Ln-Cu异金属配位聚合物。(1)利用非手性异烟酸的自发拆分合成了一个由四核稀土-氧单元和六核铜-碘单元构筑的具有二重贯穿α-Po拓扑结构的手性配位聚合物。在此基础上,通过组装规律的探索,利用烟酸配体取代反应,合成了由四核稀土-氧和六核铜-碘单元构筑的具有7-连接特征的两个手性配位聚合物,实现了相同手性晶格内金属构筑单元从6-连接到7-连接的转变;利用多核铜-碘单元结构的多样性和立方烷型四核稀土-氧单元热力学上的稳定性,合成了由纳米级十五核铜-碘单元和四核稀土-氧单元构筑的具有12-连接性的两个手性配位聚合物。(2)根据软硬酸碱规则,在Ln-CuI-异烟酸体系中引入辅助配体(如醋酸、草酸、乙醇酸、己二酸、邻苯二甲酸和对甲苯磺酸)来修饰稀土构筑单元,拓展了异金属配位聚合物的研究,得到了二十一个其它八种类型的异金属配位聚合物,它们分别是由多核稀土-氧聚集体和一维铜-碘链、一维稀土-氧链和多核铜-碘聚集体、一维稀土-氧链和一维铜-碘链、二维稀土-氧层和一维铜-碘链、多核铜-碘聚集体和一维稀土-羧酸链、一维铜-碘链和不同维度稀土-羧酸单元、二维铜-碘层和不同维度的稀土-羧酸单元、多核异金属聚集体构筑的。本论文中,过渡金属离子和稀土离子选择性地与多功能桥连配体或辅助配体中的配位原子键合,从而很好地区分了两种金属离子的化学属性,使得两种金属离子能够形成具有特定结构的构筑单元,进而组装成具有预期特征的异金属配位聚合物。本论文所提出的表面修饰策略、异金属构筑单元维度提升策略、配体导向组装策略以及异金属配位聚合物的组装规律对设计合成结构和功能新颖的金属配合物具有重要的借鉴作用。更多还原

【Abstract】 A variety of new crystals have been explored through molecular design strategies in view of their significance in the fields of fundamental and applied research. Crystal engineering involves the behavior of molecules or chemical groups in crystals, the crystal design, the control of structures and properties, and the prediction of crystal structures. It is an important approach for the fabrication of functional materials from molecules, with the help of which metal-organic coordination polymers has become a paradigm for the design of new supramolecular structures and the control of their properties. To date, the homometallic transition-metal or lanthanide coordination polymers have been widely studied. In contrast, the analogous chemistry of lanthanide-transition-metal （Ln-M） heterometals remains underdeveloped. The transition-metal ions and lanthanide ions exhibit weak selectivities under complicated coordination conditions, partially leading to homometallic complexes due to the competitive reaction between two different types of metal ions with organic ligands. Therefore, it remains a challenge for the chemists and crystallographers to select and design suitable building units and assemble them into the Ln-M coordination polymer with predictive structure and function.Three strategies including surface modification, enhanced dimension of heterometallic building unit, and ligand-directed assembly have been proposed for the study of the structures, properties and assembly principles of novel Ln-M coordination polymers. The detailed contents are listed as following:Ⅰ. Nine transition-metal and lanthanide coordination polymers have been studied by using 3-amino-1,2,4-triazole-5-carboxylate, 3,4-pyridinedicarboxylate, 1,4-benzenedicarboxylate, isonicotinate and nitrate as organic ligands.a) On the basis of bridging ligands containing carboxylate groups, two homometallic zinc coordination polymers, two Zn-Cu coordination polymers and two homometallic lanthanide coordination polymers have been synthesized. One 3D Zn-Cu coordination polymer is assembled from 2D zinc-oxygen layers and 1D copper-iodine chains, and the other is assembled from Zn-Cu-Ligand layers.b) By using nitrate as surface modification ligand, the largest hexacosanuclear lanthanide complex has been rationally synthesized, which, subsequently, has been employed to build up two supra-large tetramers. The tetramer consisting of {Dy₂₆} and {Dy₄} has been found to exhibit the slow relaxation of magnetization.Ⅱ. Nine chiral or achiral Ln-Ag coordination polymers have been studied by using isonicotinate as bridging ligand and carboxylate species as auxiliary ligand.a) Two homochiral heterometallic coordination polymers have been assembled from 1D inorganic helicates induced by silver ions as chiral units and coordination bonds beween isonicotinate and two different types of metal ions as homochiral interactions.b) Seven achiral heterometallic coordination polymers consisting of 1D inorganic heterometallic chains or lanthanide-carboxylate units have been obtained via tuning the bridging ligands and the auxiliary ligands. The results show that the coordination polymers constructed from 1D inorganic heterometallic chains by using enhanced dimension strategy exhibit target assembly characteristic and high thermal stability.Ⅲ. Twenty-six chiral and achiral Ln-Cu coordination polymers have been studied with copper-iodine complexes and lanthanide-oxygen complexes （or lanthanide-carboxylate complexes） with different geometries as bulding units, isonicotinates as directed bridging ligands and carboxylate or sulfonate species as auxiliary ligands.a) A chiral coordination polymer with two-fold interpenetratingα-Po topology has been constructed from tetranuclear lanthanide-oxygen unit and hexanuclear copper-iodine unit on the basis of the spontaneous resolution of achiral isonicotinate ligand. With the exploration of assembly principles, two seven-connected self-penetrating coordination polymers constructed from tetranuclear lanthanide-oxygen unit and hexanuclear copper-iodine unit have been rationally designed and synthesized, which implements the transformation from six-connected topology to seven-connected topology in one homochiral lattice through the nicotinate substitution. Furthermore, on the basis of the diversity of copper-iodine complexes and the thermodynamic stability of cubane lanthanide-oxygen unit, two 12-connected chiral coordination polymers have been rationally built up from nanoscale pentadecanuclear copper-iodine unit and tetranuclear lanthanide-oxygen unit.b) Based on the soft-hard/acid-base principle, various auxiliary ligands, such as acetate, oxalate, glycolate, adipate, 1,2-benzenedicarboxylate and p-toluenesulfonate, have been introduced into the Ln-CuI-Isonicotinate system to modify lanthanide structural motif, and the study on heterometallic coordination polymers has been extended to obtain twenty-one heterometallic polymers belonging to somne other eight types. These polymers are constructed from multinuclear lanthanide-oxygen complexes and 1D copper-iodine chains, 1D lanthanide-oxygen chains and multinuclear copper-iodine complexes, 1D lanthanide-oxygen chains and 1D copper-iodine chains, 2D lanthanide-oxygen layers and 1D copper-iodine chains, multinuclear copper-iodine complexes and 1D lanthanide-carboxylate chains, 1D copper-iodine chains and lanthanide-carboxylate complexes with different dimensions, 2D copper-iodine layers and lanthanide-carboxylate complexes with different dimensions, and multinuclear heterometallic complexes, respectively.In this thesis, transition-metal ions and lanthanide ions selectively bond to multifunctional organic bridging ligands or auxiliary ligands through the donor atoms, thus the chemical properties of two different types of metal ions are effectively identified, from which the building units with specific structures can be formed, leading to the formation of heterometallic coordination polymers with predictive features. The current surface modification strategy, enhanced dimension of heterometallic building unit strategy, ligand-directed assembly strategy, and heterometallic assembly principles can be heuristic in term of the design and synthesis of metal coordination complexes with novel topological architectures and functions.更多还原