Metal complexes-Polyvinylpyridines

Various combinations of macromolecules and metal components such as metal ions, metal complexes and metal chelates exist. The side of the macromolecule considers mainly organic polymers, for example, based on polystyrene, polyethyleneimine, polymethacrylic add, polyvinylpyridines, polyvinylimidazoles and others. The main chain of these polymers can be linear or crosslinked. In several cases a metal is part of the polymer chain leading to new structural units. Inorganic macromolecules like silica, different kinds... 

Polymer metal complex formation of different polyvinylpyridines in solution, in hydrogels and at interfaces were investigated [83]. In aqueous solution linear or crosslinked polyvinylpyridines in the interaction with H2PtCl6 results in reduced viscosities and reduces swelling coefficients, respectively. Complexation leads to molecular bridges and folding of the polymer. Film formation was observed at the interface of poly(2-vinylpyridine) dissolved in benzene and metal salts dissolved in water. 

Organic compounds having labile hydrogen, such as phenols, phenylenedi-amine, disulfides, and acetylene, are oxidatively coupled by metal complex to give polymeric materials as shown in Eqs. (73) and (74). These reactions are called oxidative polymerizations. Tsuchida et al. studied the oxidative polymerization of 2,6-dimethylphenol (XOH) as a redox reaction catalyzed by Cu(II)-polyvinylpyridine complexes, and have proposed a detailed mechanism [93-95]. 

Another way to functionalize the surface of microlatex particles is to incorporate amphiphilic block copolymers (for example, polystyrene/polyvinylpyridine) as cosurfactants together with the classical surfactants used in the formulation [86,87]. The protruding polyvinylpyridinium chains are anchored to the glassy core through the polystyrene blocks. These blocks copolymers were shown to stabilize the oil/water interface and to effectively bind ions of transition and heavy metals via complexation. 

The redox polymers, both of organic and inorganic origin (such as polyvinylpyridine modified by redox-active complexes of metals Prussian blue and related materials), can be considered as a version of electrodes of the second kind however, the equilibrium is usually estabhshed with respect to cations. Electron conducting polymers (polyanyline, polypyrrol, and so forth) also pertain, in the first approximation, to the electrodes of the second kind, which maintain equilibrium with respect to anion. Ion exchange polymer films on electrode surfaces form a subgroup of membrane electrodes. 

A lithium ion conducting solid electrolyte such as lithium iodide or lithium iodide-f alumina (33 mol%). The lithium iodide solid electrolyte is formed as a very thin film by directly contacting lithium metal with the positive electrode material, iodine, complexed with polyvinylpyridine. Such cells are only capable of discharge at a low rate (< 100 pAcm" ), at ambient temperatures but they perform excellently when only required to provide a low power, e.g. for a heart pacemaker. The lifetime in service can be many years and the shelf-life during storage is also long. 

The important step involves the solubilization of inorganic compounds into the micellar core. As a guideline for optimum precursor materials and micellar core blocks, one can use Pearsons hard / soft acid /base (HSAB) concept [151], which has been generalized to include metals and semiconductors [152]. The general strategy is to start from weakly coordinated metals, e.g. Pd(OAc)2 or Pd(C104)2 which are complexes of a soft acid (the transition metal ions) and a hard base (acetates, perchlorates, etc.). The formation of more stable complex of a soft acid with a softer base, e.g. polyvinylpyridine, to assemble the micellar core, is the driving force for solubilization. The polymer complex should not be too stable since over-stabilization could prevent the formation of the desired colloid in the subsequent chemical reaction. 

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