Berlin green

Berlin green, FeFe(CN)mechanism postulated for the interchange of substituents in trigonal-bipyramidal 5-co-ordinate complexes, e g. PF, and its substituted derivatives. berthoUide compound Solid phases showing a range of composition. 

The intense blue color of Pmssian Blue is attributed to electron transfer between the [Fe(CN)3] and Fe(Ill) ions. A related pigment called Berlin Green is obtained by oxidation of Pmssian Blue. It is thought that the intense color of this other compound results only if oxidation of the [Fe(CN)3] units is incomplete and some remain as hexakiscyanoferrate(4—). The compound in which only h on(Ill) is present, Fe[Fe(CN)3] [14433-93-3], is brown and is subject to autoreduction processes. 

Electrodeposited PB films may be partially oxidized102-104 to Prussian green (PG), a species historically also known as Berlin green (Equation (10)) ... 

At high anodic potentials Prussian blue converts to its fully oxidized form as is clearly seen in cyclic voltammograms due to the presence of the corresponding set of peaks (Fig. 13.2). The fully oxidized redox state is denoted as Berlin green or in some cases as Prussian yellow . Since the presence of alkali metal ions is doubtful in the Prussian blue redox state, the most probable mechanism for charge compensation in Berlin green/Prussian blue redox activity is the entrapment of anions in the course of oxidative reaction. The complete equation is ... 

The possibility for electropolymerization on the top surface of Prussian blue films was probably first shown in [126] describing the high oxidizing ability of Berlin green, the fully oxidized form of Prussian blue. Afterwards non-conducting polymers were synthesized on the top surface of transition metal hexacyanoferrate-modified electrodes for immobilization of the enzyme [127],... 

Electroreflectance spectroscopy has been successfully applied to numerous other systems such as oxide films or adsorbed dyes. It is most useful when the observed features can be related to specific electronic transitions. As an example we mention the reactions of a film of Prussian Blue adsorbed on gold or platinum. Prussian Blue can be oxidized to Berlin Green, or reduced to Prussian White. The appearance of the products gives rise to characteristic features in the electroreflectance spectra [11]. 

PB also can be oxidized to give first a green material, Berlin Green (BG), in the partially oxidized state, and then finally a yellow material, Prussian Yellow (PY), in the fully oxidized state. This oxidation typically occurs between 0.8 and 1.0 V vs. SCE. The complete oxidation of Prussian Blue to Prussian Yellow is shown in the following equation. 

Berlin blue, Mossbauer spectrum of, 6 462-464 Berlin green... 

P,2, S transition, ratio r, 35 368 Prussian Blue, 46 41 -like phases, 43 245-249 magnetic ordering, 43 246-247 magnetic properties, 43 248 relation to Berlin green, 8 120-121 structure studies on, 8 119-120 Prussiates, M6ssbauer spectrum of, 6 464-466 Pseudoazurins, 36 382 x-ray crystal structures, 36 389-390 Pseudocatalase, 40 379... 

Berlin Green Prussian Blue Everitt s salt... 

With increasing doses, we notice a peak appearing at 2170 cm [Fig. 5(a)]. This peak was assigned to the formation of iron(III) hexa-cyanoferrate(III) or Berlin green Fe [Fe "(CN) ]. 

FIG. 22.5. The relationship between (a) Berlin green, (b) Prussian blue, and (c) potassium... 

An early X-ray study of Prussian blue and some related compounds showed that in ferric ferricyanide (Berlin green), FeFe(CN)6, Prussian blue, KFeFe(CN)6. and the white insoluble K2FeFe(CN)6. there is the same arrangement of Fe atoms on a cubic face-centred lattice. In Fig. 22.5 ferrous atoms are distinguished as shaded and ferric as open circles. In (a) all the iron atoms are in the ferric state in (b) one-half the atoms are Fe and the others Fe, and alkali atoms maintain electrical neutrality. These are at the centres of alternate small cubes, and it was supposed that in hydrated compounds water molecules could also be accommodated in the interstices of the main framework. Lithium and caesium, forming... 

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