金属有机配位聚合物的合成

金属有机配位聚合物(金属聚合物)由于整合了金属和聚合物的诸多优点而在清洁能源、智能响应材料、高性能器件制备方面具有广泛的应用潜力。本文综述了近十年金属聚合物合成进展,主要从聚合物形成和金属中心引入的顺序,如先合成聚合物再引入金属中心、先合成含金属单体后引发聚合以及一步法合成金属聚合物等方面进行论述,重点介绍合成方法、金属聚合物链结构和性能之间的关系,分析了不同合成方法的优缺点,探讨了金属聚合物合成的研究趋势。     

Organometallic Polymers of the Transition Metals

This article provides a comprehensive review of the synthesis, properties and applications of organometallic polymers of the transition metals. The different classes of organometallic polymers are described according to their structural make‐up, as well as by their methods of synthesis. A number of examples of each class are given to emphasize the richness and diversity in these areas of research. In addition to linear polymers, hyperbranched, crosslinked, star and dendritic polymers are also described. The properties that transition metal‐containing organometallic polymers possess, as well as the applications that these materials have found in various domains are highlighted.

     

Thermal Characterizations of Inorganic and Organometallic Polymers

This review emphasizes the breadth of metallic and metallic-like polymers evaluated as to thermal properties. Techniques usefully applied to particular systems are noted with the aim of suggesting their application to other systems.     

History of Crystalline Polymers

The history of crystalline polymers closely parallels the development of polymer science itself. This paper discusses, in historical perspective, the work that led to the recognition that crystalline polymers exist and to the understanding of the structure, morphology, and properties that evolved. A chronological approach is taken and the cornerstones of major discoveries delineated. Initially there was a period where significant physical observations were made but could not be explained because the concept of polymers, no less crystallinity, was unheard of. Early x-ray diffraction work was extremely difficult to interpret for similar reasons. When it was established that polymers existed as bona fide molecular entities, structural analysis using classical diffraction methods soon followed. The principles of crystallization kinetics and the thermodynamics of fusion were firmly established by theory and experiment and found to have the same scientific basis as similar phenomena in low molecular weight substances. Modern emphasis has been directed to the influence of crystalline morphology on properties. The internal, interfacial, and external structures of the elementary lamella crystallite have been subject to divisive discussion for about two decades. Facts and fantasies associated with this problem are separated by considering recent experimental and theoretical results. Finally, emerging areas of research and unifying concepts are presented.     

History of Heat-Resistant Polymers

Thermally stable polymers can be traced back to the late 1950s when structures were first synthesized which could exist above 300°C in air. Perhaps the first two types of polymers most significant here were aromatic polyamides and polybenzimidazoles. The latter was important because its discovery opened the field of polyheterocycles as heat-resistant backbone functions. The impetus for this field of study was originally aerospace technology (ablation shields, coatings, and adhesives). Since that time, however, other needs have been filled with these types of polymers: high modulus fibers, flame-proof clothing, and reverse osmosis membranes. These new, unexpected advantages have provided the need for further research to replace the decrease in aerospace efforts. Research has continued, not to find a material which is more thermally stable, but to enable better processing of the polymers at hand. This change is due to a plateau seen in thermal stability (up to 600°C in air and up to 800°C in nitrogen by TGA) and to the poor tractibility observed for early heat-resistant polymers. Inorganic polymers have not been investigated in depth for these applications.     

History of Vinyl Chloride Polymers

In 1926 Semon tried to dehydrohalogenate high molecular weight poly(vinyl chloride) (PVC) in a high boiling solvent to get an unsaturated polymer which might bond rubber to metal. Unexpectedly, he obtained plasticized PVC, a flexible product inert both electrically and chemically. This discovery opened the door to the commercialization of PVC, a plastic with an annual United States production now exceeding 6 billion pounds. Special PVC's and PVC products have been developed taking advantage of the many favorable properties. Rigid structural products from house siding to pipes are becoming of increasing importance. Two main types of polymers have been utilized: 1) one prepared by suspension polymerization, and 2) a special variety prepared by colloidal polymerization and spray drying. This latter material has been especially useful for making plastisols. Plasticizers and stabilizers were developed to maximize useful and nontoxic properties. Vinyl chloride monomer (VCM) production and co-polymerization evolved as lower cost processes, higher quality products, and greater manufacturing safety were introduced. Recent challenges for the industry have included pollution and carcinogenic hazards which have been overcome by imaginative new technologies. The rate of growth of the industry is shown graphically.     

Metallogels from Coordination Complexes,Organometallic, and Coordination Polymers

A supramolecular gel results from the immobilization of solvent molecules on a 3D network of gelator molecules stabilized by various supramolecular interactions that include hydrogen bonding, π–π stacking, van der Waals interactions, and halogen bonding. In a metallogel, a metal is a part of the gel network as a coordinated metal ion (in a discrete coordination complex), as a cross‐linking metal node with a multitopic ligand (in coordination polymer), and as metal nanoparticles adhered to the gel network. Although the field is relatively new, research into metallogels has experienced a considerable upsurge owing to its fundamental importance in supramolecular chemistry and various potential applications. This focus review aims to provide an insight into the development of designing metallogelators. Because of the limited scope, discussions are confined to examples pertaining to metallogelators derived from discrete coordination complexes, organometallic gelators, and coordination polymers. This review is expected to enlighten readers on the current development of designing metallogelators of the abovementioned class of molecules.     

Reactions of Organometallic Reagents with Halogenophosphazene Cyclic Trimers,Tetramers, and High Polymers

Abstract

Three main mechanistic pathways are now evident when Grignard, organolithium, organocopper, or transition metal anions are used as reagents for reactions with halogeno-phosphazenes-substitution, metal-halogen exchange, and skeletal cleavage. Use of these reaction pathways allows the synthesis of species such as I-X. A general mechanistic theory of these reactions is presented, together with an application of these mechanisms to macromolecular synthesis.     

Charge/Discharge Properties of Organometallic Batteries Fabricated with Ferrocene–Containing Polymers

A group of ferrocene‐containing polymers were synthesized from vinylferrocene, ethynylferrocene and 1,1′‐dibromoferrocene, and properties of the formed polymers were examined to clarify their potential as a new class of cathode‐active, charge‐storage materials for rechargeable batteries. Vinylferrocene polymerized with 2,2′‐azoisobutyronitrile (AIBN) to give a polymer with number‐average molecular weights of 2 200–5 100 g · mol⁻¹ in 12–41% yields, while ethynylferrocene and 1,1′‐dibromoferrocene polymerized with Rh catalysts and by step‐growth mechanism, respectively, to provide insoluble polymers in 71–96% yields. The capacities of organometallic rechargeable cells fabricated with poly(vinylferrocene), poly(ethynylferrocene), and poly(ferrocene) reached 105, 105, and 95 Ah · kg⁻¹, respectively. In particular, poly(vinylferrocene) displayed completely reversible charge/discharge processes featuring a constant voltage of around 3.5 V.

     

Preparation of Main‐Chain‐Type Quinolinol Polymers by Organometallic Polycondensation

Summary: New main‐chain‐type polymers of 8‐quinolinol were prepared by organometallic polycondensation. They had a poly(aryleneethynylene)‐type structure and exhibited photoluminescence with a peak at about 470 nm and quantum yields of 21–39%. Metal ions such as Zn²⁺ and Al³⁺ modified the photoluminescence.

Structure of the three main‐chain‐type polymers of 8‐quinolinol synthesized and studied here.     

New Twists and Turns for Actinide Chemistry: Organometallic Infinite Coordination Polymers of Thorium Diazide

Two organometallic 1D infinite coordination polymers and two organometallic monometallic complexes of thorium diazide have been synthesized and characterized. Steric control of these self‐assembled arrays, which are dense in thorium and nitrogen, has also been demonstrated: infinite chains can be circumvented by using steric bulk either at the metallocene or with a donor ligand in the wedge.     

主链含过渡金属和大π体系的金属有机聚合物研究进展

综述了主链含过渡金属物大π体系的金属有机聚合物的研究进展。这类聚合类中比较典型的是聚茂金属。主要介绍了主链含短时隔基、长间隔基、共轭间隔基的聚茂金属的合成方法和主要特性。在聚茂金属合成方法中，着重描述了开环聚合反应方法。     

Incorporation of Fe3O4 Nanoparticles into Organometallic Coordination Polymers by Nanoparticle Surface Modification

Surface‐modified Fe ₃ O ₄ nanoparticles (NPs) can be obtained by substituting [(η⁵‐semiquinone)Mn(CO)₃] for oleylamine surface protecting groups. The resulting NP can function as a nucleus or template to generate crystalline coordination polymers that contain superparamagnetic Fe₃O₄ NPs. Hybridized magnetic properties can be obtained by introducing paramagnetic metal nodes, such as Mn²⁺, into the polymers (see picture).

     

History of the Development and Growth of Thermosetting Polymers

Fibrous proteins are cross-linked through the disulfide linkages of cystine; animal and vegetable proteins can be cross-linked by the reaction of tannic acid, chromic acid, or formaldehyde; and natural rubber can be vulcanized by heating with sulfur. However, most thermosetting polymers are synthetic polymers. These include saturated polyesters (Glyptals) synthesized by Smith in 1901, phenolic plastics produced by Baekeland in 1907, urea and melamine plastics produced by John and Henkel in 1918 and 1935, alkyds patented by Kienle in 1933, glycol maleates patented by Ellis in 1937, and epoxy resins patented by Schlack in 1933. Many of these developments were made prior to the advent of commercial synthetic thermoplastics. However, because their fabrication is more labor intensive than that of thermoplastics, thermosetting plastics now account for less than 20% of all plastics produced. Nevertheless, over 2.5 million tons of these thermosets are produced annually and the use of these cross-linked plastics continues to grow.     

A Robust Microfluidic Device for the Synthesis and Crystal Growth of Organometallic Polymers with Highly Organized Structures

A simple and robust microfluidic device was developed to synthesize organometallic polymers with highly organized structures. The device is compatible with organic solvents. Reactants are loaded into pairs of reservoirs connected by a 15 cm long microchannel prefilled with solvents, thus allowing long‐term counter diffusion for self‐assembly of organometallic polymers. The process can be monitored, and the resulting crystalline polymers are harvested without damage. The device was used to synthesize three insoluble silver acetylides as single crystals of X‐ray diffraction quality. Importantly, for the first time, the single‐crystal structure of silver phenylacetylide was determined. The reported approach may have wide applications, such as crystallization of membrane proteins, synthesis and crystal growth of organic, inorganic, and polymeric coordination compounds, whose single crystals cannot be obtained using traditional methods.