Iron blue intermediate

Iron Blue. There are three common varieties of iron blue MUoti, Chinese, and Pmssian (they are sometimes caUed toning blues). The three types differ chiefly in color, ease of dispersion, and reactivity characteristics. MUori blues are the easiest to disperse and are the least reactive. They are reddest in mass tone (plum colored) in tints, they ate intense and intermediate in redness between the Chinese and Pmssian varieties. Both the Chinese and Pmssian blues are jet in mass tone, but Pmssian blue is considerably redder and less intense in tint than Chinese blue. Because of their jet mass tones, both are used to shade blacks. Pmssian blues are the hardest to disperse and are somewhat more reactive than Chinese blues. 

The ferrooxidase site is a dinuclear iron center (see Section 8) in which two iron ions (probably Fe2+) are bound as in Fig. 16-4. They are then converted to Fe3+ ions by 02, which may bind initially to the Fe2+, forming a transient blue intermediate that is thought to have a peroxodiferric structure, perhaps of the following type.71 73 Reaction of this intermediate with H20... 

In the hydrogen-ion concentration range employed, some protonated complex is present and the dimeric species [Fe—O—Fe] + represents only 1 % of the total iron(iii). Participation of the dimer in the redox process is excluded since its formation rate is lower than the rate of the electron-transfer step. A similar scheme is postulated for the corresponding reaction of vanadium(v) (see below). The blue intermediate in the corresponding oxidation of 2-mercaptosuccinic acid (HORSH) has been characterized and is described as having a chelated (O- and S-bonded) ring structure consistent with the observed equilibrium... 

The ostrum of Vitruvius, a beautiful and costly purple color, was obtained from certain marine shell fish. It varies in shade according to the regions where found, being black in the north, as Pontus and Gaul, red in the south as at Rhodes, and blue or violet in the intermediate regions. The shellfish are collected and broken with iron tools, and the purple fluid exudes. On account of its saltness, it soon dries up unless honey is added to it. Large quanti-... 

Preparation of N-(4-carbazolyl)-p-aminophenol (intermediate for C.I. Vat Blue 43) [5] Dissolve carbazole in 95 % H2S04, cool with stirring to -28 °C with intensive cooling add to solution of / -nitrosophenol in 95% H2S04 cooled to -27 °C hold temperature at -23 °C. Add water, ice and powdered iron, using ice to hold temperature below 0°C. Stir first at -5 °C filter at 20 °C. 

During the ferroxidation reaction, a blue color with an absorption maximum of 650 run appears. This persists in oxygen-limited conditions and decays as iron oxidation proceeds. " In frog H-chain ferritin, resonance Raman studies indicate a similar absorption is associated with an Fe(III)-tyrosinate. Harrison and Treffty have considered these and other studies and attribute the transient color to formation of a /x-l,2-peroxodiferric intermediate, which decays to a more stable /x-oxodiferric species as occurs in methane monooxygenase, ribonucleotide reductase, and model compounds. Protein radicals distinct from reactive oxygen species have been observed that have been attributed to damage caused by Fenton chemistry. ... 

Oxidation of iron by EcFtnA produces a blue-colored intermediate with an absorption maximum at 650 nm and a shoulder at 370mn. This intermediate in human H-chain ferritin corresponds to a diferric peroxo species and is likely to be the same for EcFtnA, as mutation of Y24 has indicated that it caimot be an iron-tyrosinate. ... 

Corbett CM, Ingledew WJ (1987) Is Fe3+/Fe2+ cycling an intermediate in sulphur oxidation by Thiobacillus ferrooxidans FEMS Microbiol Eett 41 1-6 Cox JC, Boxer DH (1978) The purification and some properties of rusticyanin, a blue copper protein involved in iron (II) oxidation from Thiobacillus ferro-oxidans. Biochem J 174 497-502... 

The Schiff base, bis(2-pyridinal)ethylenediamine, forms a purple complex with iron(Il), but this complex too undergoes repeated hydrolytic cleavage in water. With copper(ll) a green complex is formed, which is slowly converted into a blue complex that is probably an intermediate hydrolysis product (88). 

This mechanism involves the formation of a chemical bond between the two reacting species, which may act as a bridge for the transfer of the electron. This is the less common method of electron transfer in redox reactions involving L-ascorbic acid. We have already seen that reaction of iron (in) results in the formation of an intermediate blue compound and it is likely that this is an inner-sphere electron transfer. 

Caswell No. 460 CCRIS 7331 ERA Pesticide Chemical Code 050502 Ferrous sulfate, heptahydrate Fesofbr Fesotyme Haemofort Iron protosulfate Iron sulfate heptahydrate lron(2- ) sulfate heptahydrate Iron(ll) sulfate heptahydrate Iron vitriol Ironate Irosul Melanterite mineral Presfersul Sal Martis Salt of steel Shoemaker s Black Siderotil mineral Sulfuric acid, iron(2+) salt (1 1), heptahydrate Szomolnikite mineral Tauriscite mineral. As a chemical intermediate, in electroplating, as a pesticide and medicinally as a hematinic. Registered by EPA as a herbicide (cancelled). Blue-green monoclinic crystals d n 1.897 loses H2O to form the tetrahydrate at 56.6", and the monohydrate at 65" soluble in H2O, insoluble in EtOH LDso (mus iv) n 65 mg/kg, (mus orl) = 1520 mg/kg. Generic Sigma-Aldrich Co. 

Fe -OO(H) species. A nearby glutamate residue (Glul4 in Figure lb) then displaces this peroxo moiety, leaving a blue ( max 650 nm, 550 1900 M cm ) pseudo-octahedral iron(III) center. Recently an iron(III)-peroxo intermediate was trapped in the active site of a mutant SOR, when the coordinating Glu was mutated to an Ala, and then reacted with H2O2. This transient iron(III)-peroxo species has been characterized using EPR, resonance Raman, and Mossbauer spectroscopy. 

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