History of Organometallic Polymers

In the last 20 years a wide variety of new types of polymers has been prepared containing metals as an integral part of the polymer backbone. This paper summarizes deveopments in the following major areas: vinylic polymers, including vinyl metal-locene derivatives and vinylic tin monomers; condensation polymers; polyorganophosphazenes; coordination polymers; mixed valence polymers with electrical conductivity such as (SN)_x, polyacetylene and polyphenylene; stacked polymers such as platinum blue, polyphthalocyanines, and TTF-TCNQ. The methods of synthesis and potential applications of these materials in areas such as catalysis, elastomers with low and high temperature stability, metallic conductors, semiconductors, bacteriacides, fungicides, and cancer chemotherapeutic agents are discussed.     

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。     

无机和金属有机多核分子树络合物

本文介绍近年来国外无机和金属有机多核分子树络合物的研究进展, 主要侧重于这类分子树络合物的设计合成、物化特性、催化反应及其应用前景。     

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.

     

Inorganic,Organometallic, and Organic Analogues of Carbenes

This review deals with inorganic, organometallic, and organic compounds, as well as with elements, that on the basis of their electronic structure and their reactions can be regarded formally as analogues of carbenes. These “carbene analogues” include in particular the compounds of monovalent boron, aluminum, nitrogen, and phosphorus; those of divalent silicon, germanium, tin, and lead; atomic oxygen; atomic sulfur; and atomic selenium. The preparation and chemical properties of the carbenes and their analogues are compared.     

无机金属聚合物合成及性能研究

本文报道了三类新型的无机金属聚合物—原子簇聚合物、金属配聚物和金属有机／金属配聚物的结构和性能。     

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.     

The Potential of π-Bonded Organometallic Polymers in Catalyst Design

Reductive substitution, the process whereby a hydrocarbon ligand, usually a cyclopentadienyl group, in a transition metal complex is replaced by another unsaturated hydrocarbon with concomitant metal reduction has been utilized to prepare novel complexes of Cr°, Cr^I, Mn^I, Co^I and Ni°. Similarly, ligand substitution, defined more generally as replacement of ligand(s) of a metal complex by an unsaturated hydrocarbon but with no change in the oxidation state of the metal, has resulted in the synthesis of a series of tetraphenylborate and substituted tetraphenylborate complexes of Fe^II, Mo^I, Cr^I, W^I, and Co^I. These procedures and the complexes derived therefrom are considered models for polymers incorporating a variety of novel features.     

Syntheses and Characterizations of Two Copper Coordination Polymers Constructed by 4,4''''-Bipyridine

1 INTRODUCTION Self-assembly of coordination polymers fromthe basic building blocks is of considerable interestdue to their intriguing diverse architectures and po-tential applications in catalysis and advanced mater-ials, such as magnetic, optical a…     

Characterizations and Electric Conductivities of Phosphorous Oxychloride-Treated Polymers Containing Methyl Vinyl Ketone

Abstract

Studies have been made on the characterizations and conductivities of poly(methyl vinyl ketone) (PMVK) and its copolymer with methyl methacrylate (poly(MVK-co-MMA)) after being reacted with phosphorus oxychloride (POCl₃). The POCl₃?treated polymers containing methyl vinyl ketone (MVK) were characterized by IR and UV spectroscopies to prove the structure of conjugated double bonds. The conductivities of all the MVK-containing polymers treated with POCl₃ were very low, ca. 10^?17 S/cm, in a vacuum regardless of the treatment time. The conductivities of the polymers when doped with iodine are in the range of the order of 10^?4 to 10^?6 S/cm. It was found that the conductivity of the POCl₃?treated copolymer is slightly lower than that of PMVK.     

Thermal Degradation of Natural Polymers

The thermal degradation of sodium hyaluronate, xanthan and methylcellulose was evaluated by thermogravimetric and infrared analysis. Kinetic parameters such as activation energy and pre-exponential factor were determined considering the Ozawa and Freeman–Carroll methods. The results suggest changes in the degradation mechanism with the fraction of mass loss for both the studied polysaccharides. The activation energy values determined by the Freeman–Carroll method are higher than those obtained by the Ozawa method under the same conditions, probably because in the first method a first order reaction was assumed and the thermal history effects were eliminated since only one TG curve was used to determine the kinetic parameters. Low thermal stability was observed for polyanions e.g. sodium hyaluronate (Na-Hy) and xanthan(XT) in comparison with methylcellulose (MC) which is a neutral polysaccharide. By infrared spectroscopy, it was observed that at low temperatures there occured only the scission of the exocyclic groups for both polysaccharides and that the scission of strong links in the backbone occurred at high temperatures, in agreement with the kinetic parameters determined for the degradation reaction. This revised version was published online in July 2006 with corrections to the Cover Date.     

Thermal Degradation of Glutamate Polymers

Thermal properties of precipitated samples and films of poly-γ-benzyl-L-glutamate (PBG) and poly-L-glutamic acid (PGA) have been studied using TGA, DSC, and pyrolysis. The PBG film was identified as that described by McKinnon and Tobolsky as “form C” (“film A” of Uematsu et al.) using IR, dielectric relaxation, and DSC data. The PGA film is α-helical (IR) and was further characterized by dielectric relaxation measurements. With the exception of water loss at ～110° from PGA, TGA and DSC measurements reveal only incomplete endotherms corresponding to decomposition. Volatile decomposition products were trapped and identified using combined GC/IR and GC/MS techniques. Identified products were as follows: from PGB–CO₂, NH₃, H₂O, toluene, benzaldehyde, benzyl alcohol, and benzoic acid; from PGA–CO₂, NH₃, CH₃OH, acetone, and H₂O. Only minor differences were noted in GC traces of the total volatile decomposition products in air or in nitrogen streams. No evidence for retained solvent in cast films was obtained.     

Inorganic Clusters in Organic Polymers and the Use of Polyfunctional Inorganic Compounds as Polymerization Initiators

Summary.   Silicon oxide or metal oxide clusters or small particles with polymerizable organic groups covalently bonded to their surface can be copolymerized with organic monomers by various polymerization techniques. Whereas the preparation and properties of the polymers reinforced by R ₈Si₈O₁₂ have already been well investigated, analogous materials with incorporated transition metal oxide clusters are only beginning to show their potential as an interesting new class of inorganic-organic hybrid polymers. In the second part of the article, approaches are reviewed in which the inorganic building block serves as an initiator for polymerization reactions. This results in materials in which the organic polymer is grafted from an inorganic core. Most work has been done with surface-modified silica particles. Free radical polymerizations and atom transfer radical polymerizations with macroinitiators are summarized. The latter method results in polymeric particles in which an inorganic core is surrounded by an organic polymer shell. A new approach is the use of polyfunctional inorganic molecules or molecular clusters as initiators. Received July 28, 2000. Accepted August 7, 2000     

Inorganic Coordination Polymers Based on Chalcocyanide Cluster Complexes

The paper reports results of experiments involving design of inorganic coordination polymers based on tetrahedral and octahedral chalcocyanide cluster complexes as building blocks. Various approaches to designing threedimensional, layered, and chainlike structures are discussed. Structures of various types are described, and prospects of further studies in this field are outlined.     

Novel Inorganic Coordination Polymers Based on Cadmium Oxalates

Three new cadmium oxalate coordination polymers, I-III, with extended layered structures have been synthesized in the presence of imidazole. While I was prepared by the reaction between imidazolium oxalate and Cd, II and III were synthesized from their constituents using hydrothermal methods. [Cd(C₂O₄)(C₃N₂H₄)]_∞ (I): monoclinic, space group P2₁/c (no. 14), a=8.7093(1) Å, b=9.9477(3) Å, c=8.4352 Å, β=93.796(1)°, Z=4; [Cd(C₂O₄)₂(C₃N₂H₄)₃(H₂O)]_∞ (II): monoclinic, space group P2₁/c (no. 14), a=7.8614(2) Å, b=14.9332(3) Å, c=15.9153(4) Å β=94.587(1)°, Z=4; [Cd(C₂O₄)₂(C₃N₂H₄)₃(H₂O)]_∞ (III): monoclinic, space group P2₁/c (no. 14), a=11.844(2) Å, b=9.066(1) Å, c=18.583(2) Å, β=103.84(2)°, Z=4. While the structure of I is made from CdO₅N distorted octahedra linked with oxalate, II and III are built-up from CdO₆N, CdO₅N₂ distorted pentagonal bi-pyramids connected to oxalate units. The framework formulas of II and III are identical and their structures closely related. In all the cases, the networking between the Cd-O/N polyhedra and oxalates give rise to layered architectures with the amine molecules pointing in a direction perpendicular to the layers (in the inter-lamellar region). The difference in the linkages between the oxalates and the Cd atoms in I-III, produces unusual Cd-O-Cd one-dimensional chains, which have been observed for the first time.     

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.