Fe4

Feedstuff Feed supplements Feely-Beavers procedure Feen-a-Mint Fe4[Fe(CN)6]3xH20 FEFO... 

Prussian Blue. Reaction of [Fe(CN)3] with an excess of aqueous h on(Ill) produces the finely divided, intensely blue precipitate Pmssian Blue [1403843-8] (tetrairon(Ill) tris(hexakiscyanoferrate)), Fe4[Fe(CN)3]. Pmssian Blue is identical to Turnbull s Blue, the name which originally was given to the material produced by reaction of [Fe(CN)3] with excess aqueous h on(Il). The soHd contains or has absorbed on its surface a large and variable number of water molecules, potassium ions (if present in the reaction), and h on(Ill) oxide. The h on(Il) centers are low spin and diamagnetic h on(Ill) centers are high spin. Variations of composition and properties result from variations in reaction conditions. Rapid precipitation in the presence of potassium ion affords a colloidal suspension of Pmssian Blue [25869-98-1] which has the approximate composition KFe[Fe(CN)3]. Pmssian Blue compounds are used as pigments in inks and paints and its formation on sensitized paper is utilized in the production of blueprints. 

Idiochromatic examples of this are black magnetite [1309-38-2] Fe O otherwise written as Fe(II)0 Fe2(111)02 and the analogous red Mn O and the pigments Pmssian blue [14038-43-8] and Turnbull s blue [25869-98-17, both Fe4(III)[Fe(II)(CN)2]2. Allochromatic examples are widespread in the mineral field, with Fe + + Fe + being involved in blue and green tourmaline [1317-93-7] blue iolite (cordierite) [12182-53-5] etc. 

Ferric ferrocyanide—Cl Pigment Blue 27, Cl No. 77510. The color additive ferric ferrocyanide is a ferric hexacyanoferrate is a pigment characterized by the stmctural formula Fe4[Fe(CN)g]2ArH20, which may contain small amounts of ferric sodium ferrocyanide and ferric potassium ferrocyanide. ... 

If the solution is acidified and aUtde ferric sulfate added, ferric ferrocyanide [14038-43-8], Fe4[Fe(CN)g]2, is produced. This salt has a characteristic deep blue color, and the reaction may be used to test for the cyanide. 

Figure 25.9 Some non-haem iron proteins (a) rubredoxin in which the single Fe is coordinated, almost tetra-hedrally, to 4 cysteine-sulfurs, (b) plant ferredoxin, [Fe2S2(S-Cys)4], (c) [Fe4S4(S-Cys)4] cube of bacterial ferredoxins. (This is in fact distorted, the Fe4 and S4 making up the two interpenetrating tetrahedra, of which the latter is larger than the former).

The treatment of iron carbonyls with aqueous or alcoholic alkali can, by varying the conditions, be used to produce a series of interconvertible carbonylate anions [HFe(CO)4] , [Fe(CO)4] ", [Fe2(CO)g]2-, [HFe3(CO) ]- and [Fe4(CO)i3]"". Of these the first has a distorted trigonal bipyrarmdal stracture with axial H, the second... 

Huggins (1922) assigned argononic structures to pyrite and marcasite (sexicovalent Fe4 and quadricovalent S2 ). It is evident, however, that this assignment has to be revised, as has been pointed out long ago by Buerger (1937). 

Novel boron-gold bonds containing complexes are realized in two borido clusters. Addition of [HFe4(CO)i2BH] ppn to xs (PPhjIAuCl in CH2CI2 forms the green-brown, air-sensitive Fe4(CO) 2(AuPPh,)2BH ... 

Reaction with BCI3 6.5.2.1 C36H3iAii2BFe40i2P2 Fe4(CO),2tAuP(C2Hs)3]-[AuP(C6Hs)3]BH Formation 6.4 C36H34B2P2... 

Synthetic analog clusters have played a pivotal role in development of Fe-S cluster biochemistry. Indeed, the synthesis and characterization of clusters with [Fe2( t2-S)2], [Fe4( (,3-S)4], and linear [Fe3( t2-S)4l cores by Holm and co-workers (47, 48) were crucial in establishing the properties of these clusters and identifying these types of centers in biological systems. However, the synthesis of a cluster with the physi-... 

Au-B bonds are also present in metal clusters with intersticial or peripheral boron atoms. An example is the cluster [Fe4(CO)12BH(AuPPh3)2], which was prepared by reaction of [AuCl(PPh3)] with the carbonyl iron dihydride. With the oxonium salt the reaction proceeds to the trinuclear gold derivative [Fe4(CO)12B(AuPPh3)3] (357).2063-2070 The ruthenium analogues and complexes with other ligands have been also synthesized as, for example, (358).2071-2079... 

Eine ahnliche Verbindung des Fe(III), H3[Fe4(J06)a] 6 H20, bildet sich beim Ansauern von Losungen des Na5H2[Fe(J06)2] als brauner amorpher Niederschlag (96). 

Zboril R, Machala L, Mashlan M, Sharma V (2004) Iron(III) oxide nanoparticles in the thermally induced oxidative decomposition of prussian blue, Fe4[Fe(CN)6]3. Cryst Growth Design 4(6) 1317-1325... 

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