Vinylferrocene determination

The electron richness of vinylferrocene as a monomer has been demonstrated in its copolymerization with maleic anhydride, in which 1 1 copolymers were obtained over a wide range of feed ratios and ri r2 = 0.003 [13]. Subsequent copolymerization of vinylferrocene with classic organic monomers, such as styrene [13], Ai-vinyl-2-pyrrolidone [15], methyl methacrylate [13] and acrylonitrile [13] were carried out and the Alfrey-Price Q and e parameters [16] determined. The value of e is a semiempirical measure of the electron richness of the vinyl group. The best value of e for vinylferrocene is about —2.1, which, when compared with the e values of maleic anhydride (-H 2.25), p-nitrostyrene (-1-0.39), styrene (—0.80), p-Ai,Ai -dimethyl-aminostyrene ( — 1.37) and l,T-dianisylethylene ( — 1.96), again emphasizes the electron rich nature of the vinyl group in vinylferrocene. 

Copolymerization of isopropenylferrocene with styrene, initiated by BF3 OEt2 in CH2CI2 at 0 °C, resulted in the incorporation of styrene when the styrene content of the comonomer feed exceeded 90 wt.% [18]. This result also points to the stable ferrocenyl carbocation acting as an inhibitor in the polymerization. The low level of incorporation of styrene could be attributed to the greater reactivity of the isopropenylferrocene, as also determined for vinylferrocene by Aso and Kunitake, who showed that r for vinylferrocene was greater than that of styrene [20]. 

Hunter et al [102] used both impedance and cyclic voltammetry to measure Cl for poly(vinylferrocene) films. Good agreement was found for Cl determined by the two independent techniques. Ho et al [103] had shown earlier that impedance techniques could be used to study insertion processes for intercalation oxides, but were unable to make observations at low enough frequencies to observe the redox capacity region. Mermillod et al [61] determined Cl with impedance and cyclic voltammetry on electrodes fabricated from poly(pyrrole) powders. 

Polymerization of vinylferrocene, for example, is carried out by different initiations including the Ziegler-Natta type one [3,201]. The transition metal ion such as Fe(II) can participate during the radicalic polymerization by transfer of an electron from a Fe atom to the terminal chain radical. Therefore higher values of constant of chain transfer are determined A ct/A p = 8 x 10 at 60 °C for styrene kctlkp = 6 x 10 . ... 

NaNakorn,P.,M. Suphantharika,W.Udomsopagitetal.2003.Poly(vinylferrocene)-poly(ethylene glycol) glutamate oxidase electrode for determination of L-glutamate in commercial soy sauces. World J. Microbiol. Biotechnol. 19 479—485. 

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