Macromolecular metal complexes binding

Macromolecular metal complexes can be classified into three main categories, taking into consideration the manner of binding of a metal compound to suitable macroligands [33] (Fig. 1). Type 1 metal complexes are those with the metal ion or metal chelate at a macromolecular chain, network, or surface. One possible approach to synthesize such polymers is using the polymerization of vinyl-substituted metal complexes. 

Type I A metal ion, metal complex or metal is bound to a chain of a linear or cross-linked organic or inorganic macromolecule via a covalent (at the metal), a coordinative (at the metal), a complex (at the ligand of a complex), an ionic or a 7i-bond (so-called Macromolecular Metal Complexes , Fig. 1-4). Additional possibilities exist for different kinds of binding at the surface of a carrier or the end group of a macromolecule. Examples are described in Chapters 4 and 5. 

Chapter 3 concentrates on different aspects of the formation of macromolecular metal complexes (MMCs) by interaction of a macromolecular ligand with a metal compound MX . Such metal-containing macromolecules are classified in Section 1.2.1 as type I. Chapter 4 concentrates on polymerizations of metal-containing monomers. Examples of the binding of MX at macromolecular ligands are given in more detail in Chapter 5. The kinetics and thermodynamics of formation of macromolecular metal complexes of type II, type III and type rv are not known in detail. A few aspects are included in Chapters 6, 7 and 8. 

The chemical method of synthesis of macromolecular metal complexes (MMCs) is more widespread. It is based on the chemical binding of a metal compound MX with a polymer. In this case the polymer should have corresponding reactive functional groups. The type of bond formed (donor-acceptor, covalent, ionic, etc.) is determined by the nature of the reacting components. Such a bond, as a rule, possesses a high stability (see Chapter 5). 

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]. 

Pol5nnerization of metal-containing monomers (Chapter 4) and binding of metal ions and metal complexes to macromolecular carriers (Chapter 5) are ways of having macromolecular metal complexes connected by different bonds to a macromolecular chain or network. 

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. 

Currently, two basic chemical approaches to the formation of macromolecular metal complexes (MMCs) are widely used. The first and most commonly used is based on the chemical binding of transition metal compoimds (MXJ with macroUgands... 

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. 

D. Woehrle, Binding of Metal Ions and Metal Complexes to Macromolecular Carriers, in Metal Complexes and Metals in Macromolecules, D. Woehrle, A. D. Pomogailo, Eds., p. 279, Wiley-VCH, Weinheim, 2003. 

Metal complexes or metals can be part of a macromolecular chain/network as follows binding at a macromolecule part of a macromolecule via the ligand part of a macromolecule via the metal physically incorporated into a macromolecule. This classification, first given in 1996 [1], is used throughout this book because from the numerous possibilities a metal complex or metal is easily classified by the kind of interaction it has with a macromolecule. 

Binding of Metal Ions and Metal Complexes to Macromolecular Carriers... 

Figure 5-1. Schematic representation of the binding of metal ions, metal complexes or tt-complexes at macromolecular carriers.

Metal complexes of various porphyrins 47, phthalocyanines 48 and naphthalocyanines 49, with intense absorptions in the visible region of light, have also been covalently bound to macromolecular carriers. Early work in this field was reviewed in 1977 and 1983 [124,125], These reviews, for example, reported the fixation of metal-free and metal-containing protoporphyrin-IX, chlorophyll, mesoporphyrin-IX and substituted 5,10,15,20-tetraphenyl-porphyrins. The binding of substituted phthalocyanines to substituted polymers has also been reviewed [125,126] and covers mainly the binding of carboxylic or sulfonic acid-substituted phthalocyanines to polystyrene. 

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