Iron in chloride

Chemical Designations - Synonyms Ferric Chloride (anhydrous). Ferric Chloride (hexahydrate). Iron (in) chloride. Iron perchloride. Iron trichloride Chemical Formula FeClj or FeCl3 6H20. Observable Characteristics - Physical State (as shipped) Solid Color Anhydrous greenish black, Hidrate brown Odor None. 

Fig. 1.56(a) E-i curves and experimental potential-pH diagram for Armco iron in chloride-free solutions of different pHs (A is the unpolarised potential and P the passivation potential) and (b) E—i curves and experimental potential-pH diagram for Armco iron in solutions of different pHs containing 10 mol dm of chloride ion (r is the rupture potential and p the protection potential). (After Pourbaix )... 

The cell shown in Figure 19-16 can serve as an example for calculations using Equation. One cell contains aqueous 1.00 M iron(in) chloride in contact with an iron metal electrode, and the other cell contains 1.00 M KCl in contact with a silver-silver chloride (AgCl/Ag) electrode. The half-reactions for these electrodes follow ... 

Hydrochloric acid should not be used for acidifying the alkaline solution since the yellow colour, due to the iron(m) chloride formed, causes the Prussian blue to appear greenish. For the same reason, iron(in) chloride should not be added -as is frequently recommended a suffident concentration of iron(m) ions is produced by atmospheric oxidation of the hot alkaline solution. An alternative, sensitive, test for cyanide ion is the formation of a deep purple coloration when the fusion solution is treated with an alkaline p-nitrobenzaldehyde-o-dinitrobenzene reagent. 

Direct chlorination has not beat used for the production of organyl chlorides from trialkyl- or triaryl-boranes. Chlorinolysis has been achieved by the reactions of organoboranes widi aqueous coppetfll) chloride and iron(in) chloride. However, only two of the thrM alkyl residues on boron are utilized (equation 54). Arylboranes are also converted to aryl chlorides widi coppetfll) chloride. ... 

Grimm RD, West AC, Landolt D. AC impedance study of anodically formed salt films on iron in chloride solution, J Electrochem Soc 1992 1396 1622-1629. 

Iron(in) chloride is a common impurity in commercial phosgene at the 0.08-0.2% level [1168]. Attempts to isolate an adduct between phosgene and iron(Ill) chloride were unsuccessful [1012], and a tensimetric titration of ruthenium(IIl) chloride with phosgene showed no evidence for complex formation [ICIl]. 

Cycloalkenone-2-carboxylates tautomerize to conjugated dienols in the presence of either acids or bases. Iron(III) catalysts have also been found to promote enone-dienol equilibration, and, at room temperature, dimerization . Thus, treating 87 with 1 mol% iron(in) chloride hexahydrate in methylene chloride at room temperature affords 88 in 81% yield (equation 46). The cyclohexadiene-cyclohexanone is in a rapid equilibrium with its triendiol tautomer, 89 (equation 47). 

Figure 17. Effect of stirring on potential of iron in chloride and inhibitor solution (A) started bubbling (B) stopped bubbling (T) lOW ppm NaNOt + 100 ppm NaCl 1000 ppmNogHPOi + 25 ppmNaCl) (17)...

Another way of looking at it is to consider the Pourbaix diagram Figure 7.2 (Pourbaix, 1973 Morgan, 1990) for iron in chloride solutions. This shows pH and potential changes as the iron moves from areas of corrosion to areas of passivity and then to immunity from corrosion. 

Figure 7.8 Pourbaix Diagram for Iron in Chloride Medium...

Another way of looking at the theory of cathodic protection is to look at the Pourbaix diagram (Pourbaix, 1973 Morgan, 1990) for iron in chloride solution. This shows that there are conditions where steel corrodes, and areas where protective oxides form and an area of immunity to corro.sion depending upon the pH and the potential of the steel. Ideally we would like to depress the potential sufficiently to reach the immune zone (Figure 6.2). In practice we do not do that for reasons described in the Section 6.5 on control criteria. 

Zinc extraction and separation form iron in chloride media... 

Over the past decade Zeneca (Avecia) has produced two reagents designed to recover zinc selectively from iron. The first of these, ZNX-50, was based on an imidazole structure and was proposed for the extraction and separation of zinc from iron in chloride media. The second, DS5869, is a dithiodialkylphosphoramide, and although it will separate zinc from iron in sulfate liquor it will also strongly extract cadmium, mercury, bismuth, and other soft metals and also irreversibly loads copper. These are obvious disadvantages for commercial application. 

In carbohydrate chemistry, the use of iron salts to promote a selective transformation has not always been a first choice, in spite of their being readily accessible and abundant. One of the first uses of iron(in) chloride of whieh we are aware of is the preparation of oxazoline 2, by treatment of 2-acetamido-l,3,4,6-tetra-Oacelyl-2-deo g -p-D-glucopyranose 1 with ferric chloride in dichloromethane, described by Matta and Bahl (Seheme 1). When an alcohol in excess was added to the mixture, the (3-glyeoside 3 was formed instead of the oxazoline, and this has been used on several occasions using interesting modified versions of glycosylations. ... 

A voltaic cell has an iron rod in 0.30 M iron(in) chloride solution for the cathode and a zinc rod in 0.40 M zinc sulfate solution for the anode. The half-cells are connected by a salt bridge. Write the notation for this cell. 

Aoyama, N., Manabe, K. and Kobayashi, S., Iron(in) chloride as a water-compatible Lewis acid for diastere oselective aldol reactions in water in the presence of a surfactant, Chem. Lett., 2004, 33,312-313. 

A. C. West, R D. Gtinm], D. Landolt, C. Deslouis, and B. Tribollet, Electiol dto(fynanuc impedance study of anodically fonned salt films on iron in chloride solutions, J. Electroanal. Chem. 330 693 (1992). 

---