具有纳米孔洞的金属-有机超分子聚合物与功能材料

本文介绍了近几年来一个热门的研究领域－纳米超分子笼和具有纳米孔洞的金属－有机聚合物的研究现状和发展趋势。目前该领域的研究主要集中在：设计合成有机桥联配体并与金属离子自组装成各类具有纳米孔洞的超分子化合物和一维、二维或三维的金属－有机聚合物,应用结构化学研究手段,研究它们的自组装规律、空间结构、电子结构及其物理化学性能,寻找这两类化合物在生物工程与功能材料等领域中的应用。     

新型无机聚合物的设计合成、结构规律与性能研究*

本文以新型无机聚合物的合理合成和物理性能研究为主线, 总结3个系列具有新颖结构聚合物的组装与结构化学规律: (1)通过化学自组装法设计合成出系列金属-有机纳米笼、金属-有机纳米管和金属-有机纳米线.研究了合成金属-有机纳米分子的规律,开辟了一条合成金属-有机纳米分子的新途经.(2)通过结构调控、金属与桥联基元作用,把团簇单元活化后合成一维新型无机聚合物.在研究反应机理过程中分离和表征了大量的中间态产物,从而得到了这类聚合物合理合成的规律.(3)设计合成出二维层状(石墨型)、三维大孔(分子筛型)、金属聚硫及稀土与过渡金属混合4个系列新型的无机聚合物,总结了它们的结构规律和反应规律.在制备合成中既有结构单元自组装的反应又有设计合成的方法.通过系列化合物的结构表征和光、电或磁性能的研究, 探索出系列聚合物具有半导体性能和非线性光学性能,总结出聚合物的结构规律与基本结构单元组装的关系以及结构与性能的关系.     

金属-超分子聚合物的合成,结构与应用

金属-起分子聚合物(超分子配位聚合物)是重复单元经配价键相互作用连接在一起的阵列,可由有机高分子配体和金属离子自组装形成具有多样化的几何形状和拓扑结构：线性主链均聚物、嵌段共聚物、接枝共聚物、交联聚合物、金属树枝体、栅格阵列和拓扑结构,并可对无机和金属纳米粒子进行表面修饰。金属-超分子聚合物可在光电子信息、催化、生物医用、分子器件、纳米技术等领域广泛应用。综述了金属-超分子聚合物的合成与机理、结构、性能和应用。     

聚肽胶束的超分子反应:聚合、环化及活性生长

聚合物自组装是制备纳米材料的有效途径.自组装纳米材料在药物载体、高性能材料、生物结构模型等领域具有重要的应用价值.近年来,在聚合物分子自组装研究的基础上,研究者们发展了聚合物纳米粒子的自组装研究,并取得了很大进步.聚合物纳米粒子的组装一般可称为超分子反应.以聚肽胶束为组装基元的超分子反应研究得到了很多关注,取得了一系列进展.本文以本课题组的工作为主,总结归纳了近年来在聚肽胶束自组装(超分子反应)研究方面的进展,主要包括超分子聚合、环化和活性生长.文中着重强调了理论模拟在探究胶束超分子反应中的作用.最后,本文展望了该研究领域的发展方向,并指出所面临的机遇和挑战.     

多重氢键超分子聚合物

超分子聚合物是通过单体单元间的可逆非共价作用(包括氢键、π-π相互作用和金属配位作用等)形成的,由于非共价键的方向性和强度,这类聚合物显示了许多有趣的功能,例如刺激响应性和纳米结构自组装.本文总结了近三年来多重氢键超分子聚合物在改善聚合物性能、形成复杂分子构造、自组装纳米结构等方面的作用,并对超分子聚合物的应用进行了展...     

无机-有机复合聚合物:材料研究的一个新领域

无机-有机复合聚合物特别是类分子筛聚合物、类多层钙钛矿和仿生物材料的合成及其应用研究成为近几年来一个热门的研究领域。我们瞄准了这一前沿领域并合成和表征了以下四个系列具有纳米孔洞的分子笼和一维、二维或三维的新型无机聚合物:(1)带有纳米尺寸空腔和孔状结构的新型过渡金属和稀土金属聚合物;(2)含有螺旋链的一维链状聚合物;(3)具有石墨形态层状结构和优异导电性能的聚合物;(4)以强金属-金属相互作用为核心、有机分子为稳定外壳的纳米线聚合物。本文总结这四个系列化合物的合成结构和特性。     

超支化聚合物胶束自组装

超支化聚合物因其独特的拓扑结构和物理化学性质,引起了科学界和工业界的广泛关注,成为高分子学科一个新的研究热点之一。近年来,超支化聚合物在分子自组装研究领域展示出了独特的潜力,实现了多维多尺度自组装,制备了各种超分子结构。而胶束是超支化聚合物最容易自组装得到的超分子结构。本文我们将系统总结超支化聚合物包括聚醚、聚酯、聚磷酸酯、聚多糖等胶束自组装行为、组装机理及其在生物医药、纳米载体、金属纳米粒子制备等方面的最新应用。     

多酸-有机聚合物超分子自组装杂化材料

多酸具有多样的拓扑结构和优异的理化性质,在催化、光电材料和药物等领域显示出广阔的应用前景。多酸-有机聚合物超分子自组装杂化材料不仅有效融合了多酸丰富的功能特性和有机聚合物良好的加工性,而且其有序的自组装结构还赋予材料更多优异的功能调控性。静电复合、氢键作用、共价键连等超分子策略是将多酸引入到聚合物基质中的有效方法。本文总结了多酸-有机聚合物超分子杂化材料近几年的最新研究进展,重点介绍了这类杂化材料的构筑策略、其有序的自组装行为以及超分子功能特性的调控等。     

典型锕系超分子组装体的构筑原理及研究进展

锕系超分子化学是锕系元素化学的重要研究领域,可以为乏燃料后处理的配位化学基础研究提供重要信息,并为探索锕系功能材料在发光、传感、催化和分离等方面的功能应用提供关键材料体系。本文介绍了基于锕系金属离子的金属-有机超分子组装体这一新兴领域的最新研究进展。从锕系超分子组装体的构筑原理出发并结合笔者自身研究情况,对基于主客体准轮烷配体的锕系-轮烷配位聚合物、具有闭合结构的锕系配位组装体和基于超分子相互作用的锕系超分子聚合物这三类典型的锕系超分子组装体的研究进展进行了梳理和总结阐述。期望为未来新型锕系超分子组装体的设计合成提供参考,促进相关领域的进步和发展。     

二维配位聚合物[Cd(bix)2Cl2]n的合成、晶体结构与荧光性能研究

利用金属离子和多功能的有机配体的自组装过程构筑得到的金属-有机配位聚合物,由于具有丰富的拓扑结构及其在分子与离子交换、吸附、选择性催化、光电子、磁学性能、孔洞材料、非线性光学等领域具有潜在的应用价值而成为众多科学家研究的热点领域[1～10].文献已经报道了大量具有新型拓扑结构的化合物,如一维链状、梯形、铁轨型:二维正方形或长方形格子、双层结构、砖墙结构和蜂窝状结构:三维八面体和类八面体结构、金刚石结构等.     

Supramolecular coordination chemistry of aromatic polyoxalamide ligands: A metallosupramolecular approach toward functional magnetic materials

The impressive potential of the metallosupramolecular approach in designing new functional magnetic materials constitutes a great scientific challenge for the chemical research community that requires an interdisciplinary collaboration. New fundamental concepts and future applications in nanoscience and nanotechnology will emerge from the study of magnetism as a supramolecular function in metallosupramolecular chemistry. Our recent work on the rich supramolecular coordination chemistry of a novel family of aromatic polyoxalamide (APOXA) ligands with first-row transition metal ions has allowed us to move one step further in the rational design of metallosupramolecular assemblies of increasing structural and magnetic complexity. Thus, we have taken advantage of the new developments of metallosupramolecular chemistry and, in particular, the molecular-programmed self-assembly methods that exploit the coordination preferences of paramagnetic metal ions and suitable designed polytopic ligands. The resulting self-assembled di- and trinuclear metallacyclic complexes with APOXA ligands, either metallacyclophanes or metallacryptands, are indeed ideal model systems for the study of the electron exchange mechanism between paramagnetic metal centers through extended π-conjugated aromatic bridges. So, the influence of different factors such as the topology and conformation of the bridging ligand or the electronic configuration and magnetic anisotropy of the metal ion have been investigated in a systematic way. These oligonuclear metallacyclic complexes can be important in the development of a new class of molecular magnetic devices, such as molecular magnetic wires (MMWs) and switches (MMSs), which are major goals in the field of molecular electronics and spintronics. On the other hand, because of their metal binding capacity through the outer carbonyl-oxygen atoms of the oxamato groups, they can further be used as ligands, referred to as metal–organic ligands (MOLs), toward either coordinatively unsaturated metal complexes or fully solvated metal ions. This well-known “complex-as-ligand” approach affords a wide variety of high-nuclearity metal–organic clusters (MOCs) and high-dimensionality metal–organic polymers (MOPs). The judicious choice of the oligonuclear MOL, ranging from mono- to di- and trinuclear species, has allowed us to control the overall structure and magnetic properties of the final oxamato-bridged multidimensional (nD, n = 0–3) MOCs and MOPs. The intercrossing between short- (nanoscopic) and long-range (macroscopic) magnetic behavior has been investigated in this unique family of oxamato-bridged metallosupramolecular magnetic materials expanding the examples of low-dimensional, single-molecule (SMMs) and single-chain (SCMs) magnets and high-dimensional, open-framework magnets (OFMs), which are brand-new targets in the field of molecular magnetism and materials science.     

Ligand design for multidimensional magnetic materials: a metallosupramolecular perspective

The aim and scope of this review is to show the general validity of the 'complex-as-ligand' approach for the rational design of metallosupramolecular assemblies of increasing structural and magnetic complexity. This is illustrated herein on the basis of our recent studies on oxamato complexes with transition metal ions looking for the limits of the research avenue opened by Kahn's pioneering research twenty years ago. The use as building blocks of mono-, di- and trinuclear metal complexes with a novel family of aromatic polyoxamato ligands allowed us to move further in the coordination chemistry-based approach to high-nuclearity coordination compounds and high-dimensionality coordination polymers. In order to do so, we have taken advantage of the new developments of metallosupramolecular chemistry and in particular, of the molecular-programmed self-assembly methods that exploit the coordination preferences of metal ions and specifically tailored ligands. The judicious choice of the oxamato metal building block (substitution pattern and steric requirements of the bridging ligand, as well as the electronic configuration and magnetic anisotropy of the metal ion) allowed us to control the overall structure and magnetic properties of the final multidimensional nD products (n = 0-3). These species exhibit interesting magnetic properties which are brand-new targets in the field of molecular magnetism, such as single-molecule or single-chain magnets, and the well-known class of molecule-based magnets. This unique family of molecule-based magnetic materials expands on the reported examples of nD species with cyanide and related oxalato and dithiooxalato analogues. Moreover, the development of new oxamato metal building blocks with potential photo or redox activity at the aromatic ligand counterpart will provide us with addressable, multifunctional molecular materials for future applications in molecular electronics and nanotechnology.     

Electrochemical functions of metallosupramolecular nanomaterials

Self-assembly of metal ions and organic ligands results in the formation of extended or discrete metallosupramolecular structures. In case of neutral ditopic ligands such as bisterpyridines, extended metallosupramolecular coordination polyelectrolytes (MEPEs) are formed. Metal ion-induced self-assembly of 1,4-bis(2,2':6',2'-terpyridin-4'-yl)benzene with Fe(II) or Co(II) results in MEPEs with interesting electrochemical properties. These MEPEs reversibly change their color when oxidized or reduced. The heterometallic MEPE consisting of Fe(II) and Co(II) combines the properties of the individual MEPEs and therefore shows their different states: red-purple, blue, and transparent. On the other hand, complexation of cyclic phenylazomethines with metal ions results in discrete metallosupramolecular structures. We find that metal ion assembly to the organic module occurs in a stepwise fashion because of a difference in the basicity of the imine conformers, and the metal ion assembly can be controlled electrochemically. This example illustrates how metal ion binding can be controlled by the conformation of the receptor, an important step toward assembling organic ligands and metal ions in predictable ways.     

Design and its limitations in the construction of bi- and poly-nuclear coordination complexes and coordination polymers (aka MOFs): a personal view

This article, presented from a personal point of view, is concerned with the design of ligands intended to give specifically either binuclear or tetranuclear metal complexes or coordination polymers. No attempt is made to provide a comprehensive coverage of these topics, the focus being mainly upon results from our laboratory. Some emphasis is placed upon aspects of the historical development of the deliberate construction of coordination polymers (aka MOFs)--materials promising useful applications, the study of which continues to expand exponentially. Some of our recent research is described in which the carbonate ion and the tetracyanoquinodimethane dianion are used as bridging ligands to generate targeted coordination polymers. It is intended that Dalton Perspectives be easily comprehensible to non-specialists in the field; an average second year university chemistry student should be easily able to understand the present contribution.     

1D and 2D homochiral metal-organic frameworks built from a new chiral elongated binaphthalene-derived bipyridine

Six homochiral coordination polymers 1-6 based on a new enantiopure elongated (S)-2,2'-diethoxy-1,1'-binaphthyl-6,6'-bis(4-vinylpyridine) ligand (L) and divalent metal (Zn, Cd, and Ni) connecting points were synthesized and characterized by single-crystal X-ray diffraction studies. These new homochiral coordination polymers adopt two distinct framework structures: a one-dimensional infinite chain structure with bridging L ligands occupying the axial positions of the metal centers and a two-dimensional rhombic grid structure formed by linking octahedrally coordinated metal centers with four pyridyl groups of bridging L ligands in the equatorial positions. The structures of these coordination polymers are sensitive to the nature of the anions as well as the solvents from which the coordination polymer crystals were grown. Powder X-ray diffraction studies showed that the two-dimensional chiral rhombic grids exhibited porosity, which could potentially find applications in enantioselective separations and catalysis.     

Metallosupramolecular Cube with Nanometer-sized Cavitiy

Construction of supramolecular architectures with inner cavities is a subject of current interest because of their abilities for selective inclusion of ions and molecules, molecular recognition and catalysis for specific chemical transformations. The potential use of such species largely depends on their cavity size and type, which are mainly controlled by the ligands via appropriate metal ions. A number of such species with inner cavities have been prepared and characterized. Very recently, several metallosupramolecular capsules with enclosure-like systems and very large inner cavities were reported. Herein reported are a stable neutral nanometer-sized metallosupramolecular cube cage[Ni₆(tpst)₈Cl₁₂] (1) (tpst=2,4,6-tri[(4-pyridyl)sulfanylmethyl]-l,3,5-triazine) with O_h symmetry, which was prepared from assembly reaction of NiCl₂ and the tpst ligand in DMF, and[Ag₇(tpst)₄(ClO₄)₂(NO₃)₅]_n (2) with a single stranded coordination polymer has been synthesized by self-assembly of silver salt and tpst ligand. Polymer 2 contains nanometer-sized tubes with anion and solvent molecule guests.     

配位聚合物的三阶非线性光学性质

本文概括了配位聚合物的三阶非线性光学性质，并总结了其结构与三阶非线性光学性质之间的关系。对于一维结构的配位聚合物，因配体不同或者中心金属离子的价层电子构型不同可呈现自聚焦或自散焦效应;二维结构配位聚合物的三阶非线性光学性质则与配体和中心金属离子无关，均呈现自聚焦效应;三维结构配位聚合物的自聚焦或自散焦效应主要受中心金属离子价层电子构型的影响。     

Unexpected Self‐Assembly of a Homochiral Metallosupramolecular M4L4 Catenane

Two enantiomerically pure 9,9′‐spirobifluorene‐based bis(pyridine) ligands 1 and 2 were prepared to study their self‐assembly behavior upon coordination to cis‐protected palladium(II) ions. Whereas the sterically more demanding ligand, 2 , gave rise to the expected dinuclear metallosupramolecular M₂L₂ rhombi, the sterically less demanding ligand, 1 , acts as a template to give rise to a homochiral metallosupramolecular M₄L₄ catenane.