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。     

Soft functional polynuclear coordination compounds containing pyrimidine bridges

In this account, we describe the use of simple pyrimidine derivatives in combination with metal ions to build highly structured molecular architectures containing functional nanoenvironments, cavities and surfaces that can interact with additional species. The supramolecular structure of these systems can be rationally controlled by metal fragment geometry, reaction conditions and presence of templating agents. Thus, the use of transition metals with low coordination numbers or blocked bonding positions in combination with pyrimidines (e.g. 2-hydroxypyrimidine, 4-hydroxypyrimidine, 2,4-dihydroxypyrimidine, 2-aminopyrimidine) leads to the formation of either discrete assemblies, 1D polymers or helixes. When metal ions with higher coordination possibilities are applied instead, 2D and 3D networks are generated. Some of the assemblies built in this way possess functional cavities, pores and surfaces that can interact with additional species by means of hydrophobic, electrostatic, H-bonding interactions and coordinative bonds to give rise to recognition processes. The latter range from molecular recognition in homogeneous phase as well as clathrate formation, to heterogeneous solid-gas and solid-liquid adsorption phenomena. It should be noted that these materials are not rigid but able to undergo guest-induced reorganisation processes even in the solid state. Finally, some of these materials also combine additional interesting magneto-optical properties. Thus, dual systems can be envisaged in which two or more of these properties are present in the same material.     

Flexible microporous coordination polymers

In a decade, many porous coordination polymers have been synthesized, providing a variety of properties ranging from storage, separation and exchange of guests in their cavities, magnetism, conductivity and catalysis by their frameworks. Recent advent of flexible porous coordination polymers, which exhibit elastic guest accommodation in contrast to rigid three-dimensional (3-D) frameworks of conventional porous materials, have acquired a position as a new class of porous materials. Such flexible porous properties induce highly selective guest accommodation and magnetic modulation, which could now be a unique class of practical materials. In this review, we introduce recent flexible porous coordination polymers (3-17) and their functional properties, categorizing with the four types of pores with framework deformation.     

Structure,dynamics, and solvation in a disordered metal–organic coordination polymer: a multiscale study

Metal–organic coordination polymers are a growing class of technologically-important materials in which transition metal ions are connected by multitopic organic chelators to form a 3-D network structure. While the structures of many highly-ordered metal–organic frameworks have been determined, far less structural information is available about the more common disordered materials. Our study combines pair distribution function analysis from total X-ray scattering, ab initio quantum mechanical calculations, and all-atom molecular dynamics to explore the structure and dynamics of a poorly-ordered branched coordination polymer. The polymer structure is highly flexible and dynamic, and is dramatically affected by its solvation state, a finding with far-reaching implications for the incorporation of coordination polymers into nanocomposite materials.     

Hexamethylenetetramine: An old new building block for design of coordination polymers

The design of new coordination polymers is nowadays a challenging research topic that attracts increasing interest due to the unique structural and functional properties of such metal-organic materials. In contrast to the recognized use of some N-donor ligands for the construction of coordination polymers, the application of hexamethylenetetramine (hmt) as a simple, commercially available, water-soluble and highly versatile cagelike building block has so far been explored to a lesser extent, although a considerable number of hmt-driven metal-organic networks have been reported in the last few years. Given the high potential of hmt for future developments of this research field, the present review summarizes the main structural and topological types of coordination polymers bearing hmt. These compounds feature a high diversity of topologies that include linear, zigzag, double, triple and quadruple 1D chains, rectangular grids, flat and undulating 2D layers, as well as layer-pillared, octahedral, zeolite-like, honeycomb-like and other complex 3D nets, in which hmt acts as a linker or spacer, pillar or connector, stabilizer and/or supporting ligand. The most common synthetic strategies are reviewed, showing that a diversity of metal-organic networks can be generated by facile self-assembly routes in aqueous medium and using rather simple chemicals. The main types of auxiliary ligands necessary for the construction of hmt-driven coordination networks are also identified. The additional structural features such as the formation of supramolecular networks and water clusters are described, and the selected properties and potential applications of hmt-containing coordination polymers as porous, magnetic or photoluminescent materials are highlighted.     

Synthesis and properties in solution of ruthenium(II) coordination polymers

Synthetic strategies are presented for the preparation of readily soluble ruthenium(II) coordination polymers of high molecular weight. The constitutional homogeneity of the polymers is proved using high-resolution NMR spectroscopy, and their molar masses are estimated from ¹H NMR spectra, viscosity data and SAXS investigations. The polymers are shown to be conformationally rigid, and to form either densely packed coils or rods. It is mainly this difference in shape which causes the very specific properties of the respective polyelectrolytes in the solid state as well as in dilute solution. Finally, the UV-vis absorption spectra of some of these materials are presented.     

Dynamic porous properties of coordination polymers inspired by hydrogen bonds

In a decade, many porous coordination polymers have been synthesized, providing a variety of properties ranging from storage, separation, exchange of guests in their cavities, magnetism, conductivity and catalysis by their frameworks. In this tutorial review, we focus on the hydrogen bonding type arrangements for dynamic porous coordination polymers exhibiting elastic guest accommodations, in contrast to rigid three-dimensional (3-D) frameworks. Such dynamic porous properties induce highly-selective guest accommodation and magnetic modulation, and could now be considered a new class of practical materials.     

功能配位聚合物研究进展

主要就配位聚合物在气体吸附、手性拆分和催化、分子磁体方面的研究进展进行了综述,指出配位聚合物作为潜在的新型功能材料近年来得到了科学家的普遍关注;列举了近年来这类配位聚合物的研究成果和开发进展,并对其发展前景作了展望.     

Role of solvents in coordination supramolecular systems

Solvent effect is a vital subject in the domain of coordination chemistry. In this connection, previous researches mainly focus on the role of solvents in reaction kinetics and thermodynamics during the coordination processes. In virtue of the recent efforts on coordination supramolecular systems, especially coordination polymers or metal-organic frameworks, this feature article aims to demonstrate the solvent effect on regulating such diversiform metallosupramolecular solids, incorporating their crystal growth/assembly, structural modulation, dynamic transformations, and potential applications, which may provide new insights into the rational design and construction of such advanced crystalline materials.     

Binding sites on the outside of metallo-supramolecular architectures; engineering coordination polymers from discrete architectures

Aggregation of metallo-supramolecular architectures through additional coordination is explored by introducing metal-binding units onto the outside of the supramolecular architectures. This is achieved within the framework of our imine-based approach to supramolecular architecture, by replacing the pyridylimine units with pyrazylketimine units. An advantage of the design is that it retains the ease-of-synthesis which characterises our imine-based approach. Silver(I) complexes of three pyrazylketimine ligand systems are described. The complexes demonstrate that introducing pyrazine donor units does indeed allow higher-order assembly of the distinct supramolecular architectures into engineered coordination polymers. Two distinct types of aggregation are observed. In the first, the donors on the outside of one architecture bind to the metals of another to link the units into a polymeric array. In the second type, the donors on the outside of the architectures bind to separate metal centres which are themselves not part of the architectures, and these separate metal centres link the units to form the macromolecular array. The weaker donor nature of the pyrazine nitrogens (compared to pyridine) also introduces an additional element into the design; higher coordination numbers are favoured and this can lead to arrays with higher connectivity than those observed in the discrete pyridylimine architectures.     

3d and 4d coordination complexes and coordination polymers involving electroactive tetrathiafulvalene containing ligands

The “through bond” approach has been recently developed to increase the interaction between the mobile π and localized d electrons in multifunctional molecular materials involving tetrathiafulvalene-based ligands. This article reviews the 3d and 4d coordination complexes and polymers elaborated from a library of tetrathiafulvalene derivatives containing ligands obtained recently in our group. The different synthetic ways of the complexes are highlighted as well as their chemical and physical properties.     

Polymerization of acetylenes with rare earth coordination catalysts

The polymerization of acetylene and its derivatives by rare earth coordination catalysts and the characterization of the polymers so obtained in our laboratory are reviewed. Because of the metallic conductivity possessed by doped polyacetylene and the unique properties such as conductivity (semiconductivity), paramagnetism, migration and transfer of energy and chemical reactivity and complex formation ability often shown by acetylenic polymers, which seem promising as specialty polymers, there has been considerable interest in the polymers of acetylene and its derivatives. A wide variety of catalyst systems have been developed for the polymerization of acetylenes. But there has been no information concerning the use of rare earth compounds as catalysts in the polymerization of acetylene and its derivatives. We for the first time in 1981 have succeeded in the polymerization of acetylene with rare earth coordination catalysts, which in turn is a development based upon earlier work on the diene polymerization using rare earth coordination catalysts(Ref. 1). Using rare earth catalysts, acetylene can be polymerized conveniently into high cis polyacetylene films with metallic sheen at room temperature and phenylacetylene can also be polymerized into high molecular weight, high cis polyphenylacetylene films at ambient temperature. Thus new varieties of polyacetylenes have been developed and a novel family of coordination catalysts consisting of a rare earth compound plus trialkyl aluminum for the polymerization of acetylenes has been exploited. This article reviews our studies on the polymerization of acetylene and its derivatives with rare earth coordination catalysts and on the characterization of the polyacetylenes prepared.     

含吡啶基金属-超分子聚合物研究进展

金属-超分子聚合物是由金属离子与配体之间的相互作用形成的,是一类具有多样化几何构造和拓扑结构的新型功能高分子,它包括线型、接枝、交联、树枝等多种骨架结构.金属-超分子聚合物具有光、电、磁等特性,因此潜在的应用前景非常广阔,不仅可以在生物医用、分子器件、纳米材料,还可以在催化化学反应及吸附储氢等领域获得应用.由于吡啶基团为常用配体,且近年含吡啶基团的金属-超分子聚合物研究最为广泛,最为代表性,因此,本文以聚合物结构分类对近几年含吡啶基团的金属-超分子聚合物的研究进展作了简要综述.     

Nucleotide/Tb coordination polymer nanoparticles as luminescent sensor and scavenger for nitrite ion

Newly emerged metal organic coordination polymers have aroused the great interest in designing tailored functional materials. In this study, multiple functional components, luminescent Tb³⁺ ion, nucleobase and antenna molecule, were integrated in a single material and prepared into a responsive nanoparticle for nitrite. The terbium coordination polymer nanoparticles made of this kind of material have the dual functions of recognition and transduction and obey a preset sensing mechanism without a post-functionalization of common materials. As the result of the tailored, the terbium coordination polymer nanoparticles are highly sensitive and selective to nitrite by means of Dexter energy transfer between Tb³⁺ ion and nitrite, and can be used for the scavenger for nitrite in aqueous solution. The detection limit, dynamic range and removal capacity of U–Tb–OBBA CPNPs for nitrite are 0.3 µM, 0.3–470 µM and 4.44 mg per gram of particles, respectively. Metal organic coordination polymers show an attractive potential in constructing smart sensing materials.     

Triazoles and tetrazoles: Prime ligands to generate remarkable coordination materials

The current great interest in preparing functional metal-organic materials is inevitably associated with tremendous research efforts dedicated to the design and synthesis of new families of sophisticated multi-nucleating ligands. In this context, the N-donor triazole and tetrazole rings represent two categories of ligands that are increasingly used, most likely as the result of the recent dramatic development of “click chemistry” and Zeolitic Imidazolate Frameworks (ZIFs). Thus, azole-based complexes have found numerous applications in coordination chemistry.In the present review, we focus on the utilization of 1,2,3-triazole, 1,2,4-triazole and tetrazole ligands to create coordination polymers, metal complexes and spin-crossover compounds, reported to the end of 2009. In the first instance, we present a compendium of all the relevant ligands that have been employed to generate coordination polymers and Metal-Organic Frameworks (MOFs). Due to the huge amount of reported MOFs and coordination polymers bearing these azole rings, three representative examples for each category (therefore nine in total) are described in detail. The second section is devoted to the use of the bridging abilities of these azole ligands to prepare metal complexes (containing at least two metal centers). Given the large number and the great structural diversity of the polynuclear compounds found in the literature, these have been grouped according to their nuclearity. Finally, in the last section, the triazole- and tetrazole-containing coordination compounds exhibiting spin-crossover properties are presented.     

Metal-containing conjugated oligo- and polythiophenes

Conjugated polymers containing metal groups are an important class of new materials that may find application as sensors, non-linear optical materials and in molecular electronics. Polythiophenes are an extensively studied class of conjugated polymers, that can be easily modified synthetically, and may be prepared using a variety of methods. Metal groups pendant to polythiophene backbones modulate the electronic, optical and redox properties of the conjugated backbone and can introduce novel structural motifs to these materials. Functionalization of oligo- and polythiophenes by Fe, Pd and Ru containing groups is discussed, along with the properties of some of these materials.     

Review: Lanthanide coordination chemistry: from old concepts to coordination polymers

Because of their remarkable and unmatched optical and magnetic properties, the lanthanides are under the limelight when it comes to high technology. These elements are used in strategic applications such as optical glasses and lasers, telecommunications, lighting and displays, magnetic materials, hard-disk drives, security inks and counterfeiting tags, catalysis, biosciences, and medicine, to name but a few. Long considered as minor actors in transition metal chemistry, they have now gained respect from coordination chemists who insert them into sophisticated functional and polyfunctional molecules and materials. This mini review focuses on trivalent lanthanide ions and first summarizes their basic properties. Then some classical aspects of their coordination chemistry are discussed, followed by macrocyclic chemistry, supramolecular chemistry, and self-assembly processes. The last part of this contribution deals with coordination polymers and hybrid materials including potential applications.     

Anions as templates in coordination and supramolecular chemistry

This review aims to highlight the most important recent advances in the area of anion-templated syntheses in supramolecular and coordination chemistry. We published a comprehensive review on this area in 2003 and hence examples prior to this date will only be discussed when essential for clarity of presentation. The current review has been divided into three main sections: (a) anion-templated synthesis of systems with well-defined molecular weights; this includes macrocycles and cages, interlocked species (such as catenanes and rotaxanes), helical assemblies and other selected examples. (b) Anions as templates in polymeric systems; this includes metal-organic frameworks, molecularly imprinted polymers and other selected examples, such as liquid crystalline materials. (c) Anion templates in dynamic combinatorial libraries.     

Functional porous coordination polymers

The chemistry of the coordination polymers has in recent years advanced extensively, affording various architectures, which are constructed from a variety of molecular building blocks with different interactions between them. The next challenge is the chemical and physical functionalization of these architectures, through the porous properties of the frameworks. This review concentrates on three aspects of coordination polymers: 1). the use of crystal engineering to construct porous frameworks from connectors and linkers ("nanospace engineering"), 2). characterizing and cataloging the porous properties by functions for storage, exchange, separation, etc., and 3). the next generation of porous functions based on dynamic crystal transformations caused by guest molecules or physical stimuli. Our aim is to present the state of the art chemistry and physics of and in the micropores of porous coordination polymers.