Ferrate, hexacyano-, 1:6 complex with

Practical interest in high-molecular-weight poly (propylene oxide) centers in its potential use as an elastomer (19). Copolymerization of propylene oxide with allyl glycidyl ether gives a copolymer with double bonds suitable for sulfur vulcanization. Table IV shows the properties of elastomers made with a copolymer prepared with a zinc hexacyano-ferrate-acetone-zinc chloride complex. Also shown are the properties of elastomers made from partially crystalline copolymers prepared with zinc diethyl-water catalyst. Of particular interest are the lower room-... 

Hydrated tris(phenylbiguanide)cobalt(III) chloride forms needle-shaped, red crystals which are soluble in water and alcohol but insoluble in ether and acetone. When heated to 110° for 15 hours, the hydrate loses the whole of its water to form the red anhydrous salt. The solution of the complex chloride gives colored precipitates with a number of complex anions such as hexacyanoferrate(II), hexacyano-ferrate(III), nitroprusside, hexacyanocobaltate(III), and chloroplatinate. 

Cyclic voltammetry was carried out in the presence of penta- and hexacyano-ferrate complexes in order to probe the homogeneity and conductivity of the TRPyPz/CuTSPc films (125), (Fig. 36). When the potentials are scanned from 0.40 to 1.2 V in the presence of [Fe (CN)6] and [Fe CN)5(NH3)] complexes, no electrochemical response was observed at their normal redox potentials (i.e., 0.42 and 0.33 V), respectively. However, a rather sharp and intense anodic peak appears at the onset of the broad oxidation wave, 0.70 V. The current intensity of this electrochemical process is proportional to the square root of the scan rate, as expected for a diffusion-controlled oxidation reaction at the modified electrode surface. The results are consistent with an electrochemical process mediated by the porphyrazine film, which act as a physical barrier for the approach of the cyanoferrate complexes from the glassy carbon electrode surface. 

The manganate ion is not reduced by bromide ion but is reduced slowly by iodide ion and quickly by vanadyl(IV) or hexacyano-ferrate(II) ions. When the latter two ions are used as reductants, especially with the potassium complex, green products are obtained rapidly and in high yield. The green species is unstable in solution and is apparently in equilibrium with the reactants. With potassium salts, the solubility of the product is low, and the reaction is driven to completion. Potentiometric titrations show that a one-electron reduction occurs to produce the green species, which has been characterized by analysis and optical and e.s.r. spectroscopy. It is a mixed-valence species similar to the heteropoly blues of molybdenum and tungsten. E.s.r. spectra suggest that the extra electron is fairly well trapped on a specific vanadium atom, and the complex is therefore a class II mixed-valence species.8... 

Fe + may also be characterized by the reaction it gives with the hexacyano-ferrate(II) anion [Fe(CN)6]" formerly called the ferrocyanide ion. A deep blue precipitate called Berlin blue or Prussian blue forms. It is interesting to notice that the ferrocyanide ion is a complex itself. The structure of ferric hexacyanoferrate-(II), namely, Fe4[Fe(SCN)6]3, has been ascribed to Prussian blue. 

Fig. 27 Probably the first reversible electrocheinieal switehing between the unimeric state and the self-assembled state, induced by complexation of a bis-hydrophilic polycatimi with hexacyano-ferrates in aqueous media to form vesicles PEO polyfethyltme oxide), PMOTAC polyfmethacry-loyloxyethyltrimethylammoninm chlraide) (reprinted with permission fiom [235]. Copyright 2009 American Chemical Society)...

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