Polyvinyl ferrocene

Providing an ion exchanger with a sufficient number of redox groups so that conduction can occur by a relay-type redox-change mechanism. Examples are hydroquinone-derived redox polymers and polyvinyl polymers with a tetrathia-fulvalene, ferrocene, or carbazole group, which have been found useful for research and analytical applications. 

A colloidal suspension of conductive vanadium pentoxide [130] can be used to perform intercalation, adsorption or encapsulation of electroactive molecules or biomolecules for electrodes or biosensor realization [131]. Encapsulation of glucose oxidase in nanocomposite films made with polyvinyl alcohol and V205 sol-gel matrix or in ferrocene intercalated V2Os sol-gel [132] were envisaged to prepare glucose biosensors. 

Constantinos G. Tsiafoulis et al. report the electrochemical behaviour of a composite film based on ferrocene intercalated V205.nH20 xerogel (FeCp2-VXG) with photocrosslinkable polyvinyl alcohol with styrylpyridinium residues (PVA-SbQ), in order to be used as an electrocatalyst and host protein platform to develop an amperometric biosensor. 

The landmark discovery of ferrocene by Kealy and Paulson in 1951 marked the beginning of modern organometallic chemistry. The first organometallic addition polymer was polyvinyl-ferrocene synthesized by Arimoto and Haven in 1955. While polyvinylferrocene (structure 11.32) had been synthesized it was about another decade until the work of Pittman, Hayes, and George, and Baldwin and Johnson allowed a launch of ferrocene-containing polymers. 

Electrochemical doping of insulating polymers has been attempted for polyacetylene, polypyrrole, poly-A/-vinyl carbazole and phthalocyaninato-poly-siloxane. Significantly, Shirota et al. [91] claim to have achieved the first synthesis of electrically conducting poly(vinyl ferrocene) by the method of electrochemical deposition (ECD) [91]. This is based on the insolubilization of doped polymers from a solution of neutral polymers. A typical procedure applied [91] for polyvinyl ferrocene is to dissolve the polymer in dichlorometh-ane and oxidize it anodically with Ag/Ag+ reference electrode under selective conditions. The modified polymer [91] (Fig. 28) is a partially oxidized mixed valence salt containing ferrocene and ferrocenium ion pendant groups with C104 as the counter anion. 

Other materials being investigated include ferrocene with a bipyridinium salt,234 niobium oxide,235 nickel oxo-hydroxide,236 and cobalt oxohydroxide.237 The last is pale yellow in the reduced state and dark gray in the oxidized state. A typical electrolyte is lithium perchlorate in propylene carbonate. Solid electrolytes, such as a lithium salt (perchlorate, tetrafluoroborate, or triflate), in a polyepoxide238 or in a polyvinyl chloride gel in ethylene carbonate-propylene carbonate,239 lithium iodide in polyvinyl bu-tyral,240 and Naflon H (a polymeric perfluorocarbon-sulfonic acid),241 have also been tested. Some other systems use suspended particles between two panes of glass.242 When the particles are aligned by an electric field, the window becomes transparent. Combination photo-voltaic-electrochromic devices are under study.243... 

Ferrocene fer-6- Sen [ferro- -F cycV -F -ene] (1952) (dicyclopentadienyl iron) n. (C5H5)2pe. A coordination compound of ferrous iron and cyclopentadiene, soluble in PVC and stable to 400°C. Its uses include smoke suppression, a curing agent for silicone resins, an intermediate for high-temperature polymers, and an ultraviolet absorber. Wickson EJ (ed) (1993) Handbook of polyvinyl chloride formulating. John Wiley and Sons Inc., New York. 

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