Ferrous chlorides

Absolute diethyl ether. The chief impurities in commercial ether (sp. gr. 0- 720) are water, ethyl alcohol, and, in samples which have been exposed to the air and light for some time, ethyl peroxide. The presence of peroxides may be detected either by the liberation of iodine (brown colouration or blue colouration with starch solution) when a small sample is shaken with an equal volume of 2 per cent, potassium iodide solution and a few drops of dilute hydrochloric acid, or by carrying out the perchromio acid test of inorganic analysis with potassium dichromate solution acidified with dilute sulphuric acid. The peroxides may be removed by shaking with a concentrated solution of a ferrous salt, say, 6-10 g. of ferrous salt (s 10-20 ml. of the prepared concentrated solution) to 1 litre of ether. The concentrated solution of ferrous salt is prepared either from 60 g. of crystallised ferrous sulphate, 6 ml. of concentrated sulphuric acid and 110 ml. of water or from 100 g. of crystallised ferrous chloride, 42 ml. of concentrated hydiochloric acid and 85 ml. of water. Peroxides may also be removed by shaking with an aqueous solution of sodium sulphite (for the removal with stannous chloride, see Section VI,12). 

Sa.lts Salting out metal chlorides from aqueous solutions by the common ion effect upon addition of HCl is utilized in many practical apphcations. Typical data for ferrous chloride [13478-10-9] FeCl2, potassium chloride [7447-40-7] KCl, and NaCl are shown in Table 9. The properties of the FeCl2-HCL-H2 0 system are important to the steel-pickling industry (see Metal SURFACE TREATMENTS Steel). Other metal chlorides that are salted out by the addition of hydrogen chloride to aqueous solutions include those of magnesium, strontium, and barium. 

Iron oxide yellows can also be produced by the direct hydrolysis of various ferric solutions with alkahes such as NaOH, Ca(OH)2, and NH. To make this process economical, ferric solutions are prepared by the oxidation of ferrous salts, eg, ferrous chloride and sulfate, that are available as waste from metallurgical operations. The produced precipitate is washed, separated by sedimentation, and dried at about 120°C. Pigments prepared by this method have lower coverage, and because of their high surface area have a high oil absorption. 

Diphenylamine is manufactured by the self-condensation of aniline in the presence of a small amount of a mineral acid, such as anhydrous hydrogen chloride, or Lewis acids, such as ferrous chloride or ammonium bromide. 

Several modifications to this process are possible (55). Instead of adding ferrous chloride directiy, it is more common to generate it by using iron and hydrochloric acid. The order in which the reactants are added can also be altered, and it is even possible to add all of the iron or aniline at the beginning of the reaction. There are also other ways to recover the aniline from the iron oxide sludge. 

Hydrogenation of cinnamaldehyde has been studied extensively since selectivity has often been an issue. Under mild conditions the carbonyl group is reduced giving cinnamyl alcohol, whereas at elevated temperatures complete reduction to 3-phenylpropanol [122-97 ] results. It is possible to saturate the double bond without concomitant reduction of the carbonyl group through selective hydrogenation with a ferrous chloride-activated palladium catalyst (30), thereby producing 3-phenylpropanol [104-53-0]. 

The effect of chemical reaction in reducing the effect of variation of the liquid rate on the rate of absorption in the laminar-flow regime was illustrated by the evaluation of the rate of absorption of chlorine in ferrous chloride solutions in a wetted-waU column by Gilliland, Baddoiir, and White [Am. In.st. Chem. Eng. J., 4, 323 (1958)]. 

Ferrous chloride (4H2O) [13478-10-9] M 198.8, m 105°(dec), pKj 6.7, pKj 9.3 (for aquo Fe " "). A 550mL round-bottomed Pyrex flask was connected, via a glass tube fitted with a medium porosity... 

The cooled contents of the 2S0-ml. flask containing ferrous chloride (Note 6) are added to the cold sodium cyclopentadienide solution while passing a stream of nitrogen through both flasks. The combined mixture is stirred for 1.25 hours at a temperature just below reflux. Solvent is removed by distillation, and the ferrocene is extracted from the residue with several portions of refluxing petroleum ether (b.p. 40-60°). The product is obtained by evaporation of the petroleum ether solution. Ferrocene may be purified by recrystallization from pentane or cyclohexane (hexane, benzene, and methanol have also been used) or by sublimation. The 3ueld is 31-34 g. (67-73%) (Note 7), m.p. 173-174°. 

The quality of the iron used in preparing the ferrous chloride has a marked effect on the yield of ferrocene. The checkers employed Rascher and Betzold (730 N. Franklin, Chicago, 111.) 300-mesh iron powder, reduced by hydrogen. When 40-mesh iron filings were used, the yield of ferrocene was much lower (ca. 33%). 

Ferrous chloride may be substituted by ferric chloride directly, with a corresponding reduction in yield, since the sodium cyclopentadienide solution will reduce ferric chloride. 

The methods of preparation of ferrocene have been reviewed by Pauson and by Fischer. Ferrocene has been made by the reaction of ferric chloride with cyclopentadienylmagnesium bromide, by the direct thermal reaction of cyclopentadiene with iron metal, by the direct interaction of cyclopentadiene with iron carbonyl, by the reaction of ferrous chloride with cyclopentadiene in the presence of organic bases such as diethyl-amine, by the reaction of ferrous chloride with sodium cyclo-[lentadienide in liquid ammonia, and from cyclopentadiene and... 

The conditions given in the preceding preparation are used for obtaining a suspension of 0.25 mole of ferrous chloride in 100... 

Iron chlorides (ferric chloride, ferrous chloride)... 

Chemical Designaflons - Ferrous chloride tetrahydrate. Iron dichloride. Iron protochloride ... 

Dibromo adducts have been used for many years for purifying olefins. Reduction with zinc or iodide has been the traditional way of regenerating the olefin, although occasionally other reagents, ferrous chloride, for example, have been employed. Zinc is usually effective and may be used in acetic acid in favorable cases. Milder conditions are necessary if sensitive groups are present (ref. 185, p. 51). A well known application of the protective function... 

Using two synthetic routes—i.e., interaction of iron with pyrrole in the vapor phase and reaction of ferrous chloride with sodium pyrrolate—ECj (pyrrolate)y was... 

Chlorechtheit, /. fastness to chlorine. Chloreisen, n. iron chloride, specif, ferric chloride. -oxyd, n. ferric chloride, iron(III) chloride, -oxydui, n, ferrous chloride, iron(II) chloride,... 

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