Prussian blue for

E.A. Puganova and A.A. Karyakin, New materials based on nanostructured Prussian blue for development of hydrogen peroxide sensors. Sens. Actuators B chem. 109, 167-170 (2005). 

In 2003, the FDA approved Prussian blue for the treatment of contamination with radioactive cesium (137Cs) and intoxication with thallium salts. Approval was prompted by concern over potential widespread human contamination with radioactive cesium caused by terrorist use of a radioactive dispersal device ("dirty bomb"). The drug is part of the Strategic National Stockpile of pharmaceuticals and medical material maintained by the CDC... 

Thompson DF, Called ED Soluble or insoluble Prussian blue for radiocesium and thallium poisoning Ann Pharmacother 2004 38 1509. [PMID 15252192]... 

The colorants for all the flags was found to be consistently cochineal for the reds and Prussian Blue for the blues. Although the... 

United States Food and Drug Administration, Center for Drug Evaluation and Research. Guidance for Industry on Prussian Blue for Treatment of Internal Contamination with Thallium or Radioactive Cesium, Avarlabrtity. Federal Register/Vol. 68, No. 23/Tuesday, February 4, 2003/Notices, http //www.fda.gov/OHRMS/DOCKETS/98fr/03-2597.pdf, last accessed 1-01-06... 

It is essential to use an excess of sodium, otherwise if sulphur and nitrogen are both present sodium thiocyanate, NaCNS, may be produced in the test for nitrogen it may give a red coloration with ferric iron but no Prussian blue since there will be no free cyanide ions. With excess of sodium the thiocyanate, if formed, will be decomposed ... 

Hydrochloric acid should not be used for acidifying the alkaline solution since the yellow colour, due to the ferric chloride formed, causes the Prussian blue to appear greenish. For the same reason, ferric chloride should not be added—as is frequently recommended a sufficient concentration of ferric ions is produced by atmospheric oxidation of the hot alkaline solution. The addition of a little dfiute potassium fluoride solution may be advantageous in assisting the formation of Prussian blue in a readily filterable form. 

If sulphur is present, a black precipitate of ferrous sulphide is obtained when the ferrous sulphate crystals dissolve. Boil the mixture for about 30 seconds, and acidify with dilute sulphuric acid the ferrous sulphide dissolves and a precipitate of Prussian blue forms if nitrogen is present. 

Nitrogen. Treat one portion with 1-2 ml. of 5 per cent, sodium hydroxide solution and 0 1 g. of powdered ferrous sidphate. Boil for 1 minute and cool. Cautiously acidify with dilute sulphuric acid (carbon dioxide is evolved). A precipitate of Prussian blue indicates that nitrogen is present. 

Sodium ferrocyanide (IOH2O) [13601-19-9] M 484.1, m 50-80 (ioses lOHjO), 435 (dec), d 1.46, pK 2.57, pK4 4.35 (for ferrocyanide). Crystd from hot water (0.7mL/g), until free of ferricyanide as shown by absence of Prussian Blue formation with ferrous sulfate soln. 

The CK" ion can act either as a monodentate or bidentate ligand. Because of the similarity of electron density at C and N it is not usually possible to decide from X-ray data whether C or N is the donor atom in monodentate complexes, but in those cases where the matter has been established by neutron diffraction C is always found to be the donor atom (as with CO). Very frequently CK acts as a bridging ligand - CN- as in AgCN, and AuCN (both of which are infinite linear chain polymers), and in Prussian-blue type compounds (p. 1094). The same tendency for a coordinated M CN group to form a further donor-aceeptor bond using the lone-pair of electrons on the N atom is illustrated by the mononuclear BF3 complexes... 

Polynuclear transition metal cyanides such as the well-known Prussian blue and its analogues with osmium and ruthenium have been intensely studied Prussian blue films on electrodes are formed as microcrystalline materials by the electrochemical reduction of FeFe(CN)g in aqueous solutionThey show two reversible redox reactions, and due to the intense color of the single oxidation states, they appear to be candidates for electrochromic displays Ion exchange properties in the reduced state are limited to certain ions having similar ionic radii. Thus, the reversible... 

Originally, compounds containing coordination complexes were given common names such as Prussian blue (KFe[Fe (CN)g ]), which is deep blue, or Reinecke s salt (NH4[Cr (NH3)2 (NCS)4]), named for its first maker. Eventually, coordination compounds became too numerous for chemists to keep track of all the common names. To solve the nomenclature problem, the International Union of Pure and Applied Chemistry (lUPAC) created a systematic procedure for naming coordination compounds. The following guidelines are used to determine the name of a coordination compound from its formula, or vice versa ... 

K+ is generally used as the reversibly intercalating ion since it leads to insoluble compounds for all the forms. In the mixed-valence Prussian Blue compound, Fe is in the high-spin state and coordinated octahedrally with the N ends of the cyaiudes, whereas Fe is low-spin and octahedrally coordinated with the C ends of the... 

In the first experiment 10 ml of 500 ppm solutions of FeCl3 were sonicated for 15, 30, 45 and 60 min. To examine the reduction of Fe(III) to Fe(II), 0.1 ml of the sonicated sample was transferred to a 10 ml volumetric flask and mixed with 0.5 ml of 2,000 ppm K3[Fe(CN)6] solution before making up to the mark with distilled water. Final concentration of this sonicated sample in 10 ml of volumetric flask was 5 ppm. UV-vis absorbance at >.max 795 was recorded. Sonication reduced Fe3+ to Fe2+, which reacted with K3[Fe(CN)6], already added in the solution, to form blue colour due to prussian blue. Continuous sonication gradually increased the concentration and intensity of prussian blue complex, as is clear from the Table 10.1. 

Following a published procedure for converting substituted anilines to isatins by reaction with chloral hydrate and hydroxylamine [1], it was noticed that at the end of the first stage (formation of an isonitrosoacetanilide), the odour of hydrogen cyanide was present, and this was confirmed by a Prussian blue test [2], In related work, concentrations of 100-200 ppm of hydrogren cyanide were found [3]. A mechanism for its formation from chloral hydrate and hydroxylamine was proposed [2], and the need for appropriate precautions was stressed [2,3],... 

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