Macromolecular metal complexes properties

Techniques for the quantitative investigation of the dynamic processes involved, as well as of the physiochemical properties of macromolecular metal complexes, are... 

This book provides an overview of possible combinations of metal complexes and metals with organic and inorganic macromolecules (often also named macromolecular metal complexes — MMC [1]). This book covers the formation, synthesis, structure and properties of these exciting and relatively new materials. Metal-containing macromolecules are a fascinating field of science. It is readily understandable that materials with unusual properties are obtained by having a metal complex or metal as part of a macromolecule. Nature shows us the functions of such materials extremely well by the selectivity and activity of, for example, hemoglobin, photosynthesis and metalloenzymes. 

The application of catalytic systems based on macromolecular metal complexes is one of the attractive lines of development of metal complex catalysis [1-7]. The use of macromolecular fragments in a metal complex catalyst enables one to substantially change the microenvironment of the catalytic site and, thereby, the catalytic properties of the metal complex. The main role in such a change (as, for example, in enzymes) is played by the submolecular structures formed by macromolecular metal complexes. These structures can selectively bind the substrate, alter the geometry and the energy of the transition state and cause mutual activation of the participants in the cataMic reaction [1]. 

Macromolecular metal complexes of dendrimers have a number of properties, which make them promising for use in catalysis. Firstly, they are relatively readily separable from the reaction products by precipitation with a poor solvent or by membrane filtration. Secondly, the introduction of catalytically active sites into dendrimers is controllable in this they resemble terminally functionalized polymers. The dendrimer structure allows us to purposefully introduce catalytically active groups into the dendrimer core, onto the outer surface, or in intermediate positions. The introduction of cataljdically active groups to the outer surface makes them accessible to reaction and enables us to obtain a catalyst that has a high metal content owing to the dendrimer structure. The introduction of catalytically active... 

Chapters 1 and 2 of Part A PREFACE introduce into definitions, classifications, history, properties and biological systems of macromolecular metal complexes. Then part B SYNTHESIS AND STRUCTURES contain at first in chapter 3 kinetics and thermodynamics of formation of these complexes. The following chapters 4 till 8 describe in detail the various synthetic routes for the preparation of macromolecular metal complexes. Part C with chapters 9 till 14 is devoted to PROPERTIES. The most important ones are binding of small molecules, physical and optical sensors, catalysis, photocatalysis and electron/photon induced processes. In chapter 15 few closing remarks are made. 

In metal-containing macromolecules or macromolecular metal complexes (MMC) (article in the previous edition of the Handbook see [1]) suitable compounds are combined to materials with new unusual properties organic or inorganic macromolecules with metal ions, complexes, chelates or also metal clusters. These combinations result in new materials with high activities and specific selectivities in dilferent functions. This article concentrates on synthetic aspects of artificial metal-containing macromolecules. Properties are shortly mentioned, and one has to look for more details in the cited literatures. In order to understand what kind of properties are realized in metal-containing macromolecules, in a first view functions of comparable natural systems (a short overview is given below) has to be considered ... 

The main usage of macromolecular metal complexes is catalysis." Some important characteristics of immobilized catalysts are fimctional group distribution, their accessibility, and the uniformity of their bonding properties. These characteristics and their response to reaction conditions reflect the latent properties of immobilized catalysts and have been given the term topochemistry of macromolecular metal complexes. 

The metal complexes attached to synthetic polymers or macromolecular metal complexes often show specific behavior in the binding reaction of small or gaseous molecules, because the reactions are affected by the polymers that surround the complex moieties [1-3]. Polymer immobilization of these metal complexes and the properties of the polymer complexes have a strong affect on the kinetic, equilibrium, and lifetime profile of the gaseous molecule-binding reactions. 

Used widely in synthetic macromolecular and natural biopolymer fields to evaluate structural and thermodynamic properties of macromolecular materials, thermal analytical methods have been applied to assist in the characterization of natural organic matter (NOM). Originally applied to whole soils, early thermal studies focused on qualitative and quantitative examination of soil constituents. Information derived from such analyses included water, organic matter, and mineral contents (Matejka, 1922 Tan and Hajek, 1977), composition of organic matter (Tan and Clark, 1969), and type of minerals (Matejka, 1922 Hendricks and Alexander, 1940). Additional early studies applied thermal analyses in a focused effort for NOM characterization, including structure (Turner and Schnitzer, 1962 Ishiwata, 1969) and NOM-metal complexes (e.g., Schnitzer and Kodama, 1972 Jambu et al., 1975a,b Tan, 1978). Summaries of early thermal analytical methods for soils and humic substances may be found in Tan and Hajek (1977) and Schnitzer (1972), respectively, while more current reviews of thermal techniques are provided by Senesi and Lof-fredo (1999) and Barros et al. (2006). 

Nature shows how complicated it is to construct metal-containing macromolecules that are active but also selective with respect to a specific property. Natural systems do not need to exhibit a high stability towards storage and heat because the active materials are readily replaced. On the other hand, artificial systems must be more stable over time and towards heat. Therefore extreme demands are placed upon artificial metal-containing macromolecules. It IS important to point out that the fundamental behaviors of low molecular weight metal complexes will be shown also in macromolecular analogues. But these behaviors, and thus the properties, are strongly influenced by the kind of macromolecular environment or the kind of incorporation into a macromolecule. 

Type IV metal-containing macromolecules involve metal nanoparticles or metal complexes physically incorporated in macromolecules. The properties are general influenced greatly by the kind of macromolecular environment ... 

A.D. Pomogailo, Immobilization of Metal Complexes on Macromolecular Supports. Catalytic Properties of Immobilized Systems in Polymerization Processes, Doctoral Dissertation, Institute of Chemical Physics, Moscow, 1981. 

The extraordinary materials metal complexes and metals in macromolecules have reached the scientific standard of an interdisciplinary and natural science. Based on the high level of synthetic procedures and detailed structural characterizations, a more intensive investigation of structure-property relationships is now possible. This will open new areas and contribute efficiently to new processes of fundamental technical importance for synthetic materials. The key for all these developments is the metal complex/metal as the active part in a well-defined macromolecular environment. 

Ionic LCs are interesting systems because they combine the properties of LCs with those of ionic liquids. Although alkali metal soaps were among the first thermotropic LCs to be systematically studied, ionic liquid crystalline derivatives have been reported less frequently than those based on neutral molecular and macromolecular species [39]. When the halide of [AuX(CNR)] complexes is substituted by a second isocyanide, ionic complexes [Au(CNR)2][Y] [R = C6H40C H2 + i (27a),... 

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