I chloride

Submitted by Robert E. Buckles and Jane M. Bader Checked by Wendell W. Hess  

Iodine (I) chloride can be prepared by the direct interaction of gaseous chlorine with solid iodine so that equimolar amounts of the two elements react together. The product is used without purification, or it is purified by fractional freezing and distillation. The net result of application of these methods of synthesis has been that with no purification the product has been unsatisfactory for many uses, and with too much handling—especially with distillation—the product has also been unsatisfactory. Excessive handling of iodine (I) chloride can give rise to the evolution of chlorine and thus to the reversal of the reaction of synthesis. It can also allow more chance of contact with water so that iodine (V) oxide (a relatively insoluble white solid) forms as a contaminant  

Rapid or uneven freezing or vaporization of iodine (I) chloride gives rise to the formation of iodine(III) chloride (a 

Chlorine is passed slowly through the mass of iodine crystals. As the reaction mixture becomes fluid, the rate of chlorine addition can be increased to some extent, but 

Solid iodine (I) chloride is usually obtained as the a-form, the melting point of which has been reportedas 27.2°. A /3-modification (m.p. 13.9°) has also been described. Values for its boiling point vary from 94.7 to 102°, because of decomposition into chlorine and iodine. This tendency toward decomposition and the relatively low melting point have hindered the accurate determination of sample weights. In current practice, crystalline iodine (I) chloride 

Submitted bt R. N. Kbixer and H. D. WtcoffI Chbceed bt Louis E. Marchi  

No copper(I) salts soluble in water to give copper(I) ions, Cu , are known. The only known stable copper (I) salts 

To a stirred solution of 10 g. of copper(II) chloride, CuCl2-2H20, in 10 ml. of water is added slowly at room temperature a solution of 7.6 g. of anhydrous sodium sulfite, Na2SOs, in 50 ml. of water. The copper(II) chloride solution first becomes very dark brown, and then white copper (I) chloride slowly separates. After all the sodium sulfite solution has been added and the mixture stirred thoroughly, the copper (I) chloride settles readily and the supernatant liquid is faintly green. The precipitate and supernatant liquid are then poured into about a liter of water to which 1 g. of sodium sulfite and 2 ml. of concentrated hydrochloric acid have been added, and the mixture is stirred well and allowed to stand until aU the copper (I) chloride has settled. The supernatant liquid is carefully decanted and the precipitate is quickly washed onto a suction filter (sintered glass type preferred) with dilute sulfurous acid solution. Care should be taken that a layer of liquid covers the salt in the funnel at aU times. 

The copper(I) chloride is then washed four or five times with 20 to 25 ml. of glacial acetic acid. During this washing process the suction should be adjusted so that the wash liquid is sucked through rather slowly. When only a thin film of liquid covers the solid, the next portion of glacial acetic acid is added. The walls of the funnel should be washed each time with the washing liquid. The washing 

The copper (I) chloride prepared by this method is a white crystalline powder that remains practically unchanged for an indefinite period if kept dry. If all the alcohol is not removed during the washing process, the copper(I) chloride may become slightly discolored on heating or standing. Some samples of anhydrous ether tend to impart a gray tint to the product. 

Retraso, S. Bonanno, S. Caronna, S. Ciofalo, M. Maggio, B. Schillaci, 

Ohshita, J., ChertL Lett. 2001, 1228. 

Solubility insol H2O and most organic solvents partially sol dimethyl sulfide (DMS). 

Form Supplied in light green-tinged white solid 99.99% grade available commercially. 

FLandling, Storage, and Precautions maintenance of a dry N2 or Ar atmosphere is recommended. 

---

Copper I) chloride, CuCl. White solid (CuClj plus HCJ plus excess copper or SO2). Gives carbonyl and phosphine complexes. 

JiVith ammoniacal or hydrochloric acid solution of copper(I) chloride, carbon monoxide forms the addition compound CuCl. CO. 2H2O. This reaction can be used to quantitatively remove carbon monoxide from gaseous mixtures. 

In presence of hydrochloric acid, tin(II) in aqueous solution (1) is precipitated by hydrogen sulphide as brown SnS, and (2) will reduce mercury(II) chloride first to mercury(I) chloride (white precipitate) and then to metallic mercury. 

Halogens can act as ligands and are commonly found in complex ions the ability of fluorine to form stable complex ions with elements in high oxidation states has already been discussed (p. 316). However, the chlorides of silver, lead(Il) and mercury(l) are worthy of note. These chlorides are insoluble in water and used as a test for the metal, but all dissolve in concentrated hydrochloric acid when the complex chlorides are produced, i.e. [AgCl2] , [PbC ] and [Hg Clj]", in the latter case the mercury(I) chloride having also disproportionated. 

In both cases the copper(I) chloride dissolves in the acid to form the complex [Cu C ] + On pouring the brown solution into water. 

Measurements on copper) I) chloride show the vapour to be the dimer of formula CU2CI2, but molecular weight determinations in certain solvents such as pyridine show it to be present in solution as single molecules, probably because coordination compounds such as py -> CuCl (py = pyridine) are formed. 

The solid readily dissolves chemically in concentrated hydrochloric acid, forming a complex, and in ammonia as the colourless, linear, complex cation [H3N -> Cu <- NHj] (cf AgCl) if air is absent (in the presence of air, this is oxidis to a blue ammino-copper(II) complex). This solution of ammoniacal copper(I) chloride is a good solvent or carbon monoxide, forming an addition compound CuCl. CO. H2O, and as such is used in gas analysis. On passing ethyne through the ammoniacal solution, a red-brown precipitate of hydrated copper(I) dicarbide (explosive when dry) is obtained ... 

The complexes of copper(I) like those of silver(I) (p. 430), but unlike those of preceding transitions metals, tend to prefer a linear coordination of two ligands, i.e. X—Cu—X thus copper(I) chloride in aqueous ammonia gives the colourless [Cu(NH3)2] (readily oxidised in air to give blue [Cu (NH3)4(H20)2] copper(I) chloride in hydrochloric acid gives [CuClj], although [CuCl3] is also known. 

The aqueous solution has a low conductivity, indicating that mercury(II) chloride dissolves essentially as molecules Cl—Hg—Cl and these linear molecules are found in the solid and vapour. A solution of mercury(II) chloride is readily reduced, for example by tin(ll) chloride, to give first white insoluble mercury(I) chloride and then a black metallic deposit of mercury, The complexes formed from mercury(II) chloride are considered below. 

Give the name and formula of one ore of mercury. How is the metal (a) extracted from this ore, (b) purified Starting from the metal, how would you prepare specimens of (c) mercury(I) chloride,... 

To a solution (note 2) of 2 g of copper(I) chloride (commercial product) and... 

Although It IS possible to prepare aryl chlorides and aryl bromides by electrophilic aromatic substitution it is often necessary to prepare these compounds from an aromatic amine The amine is converted to the corresponding diazonmm salt and then treated with copper(I) chloride or copper(I) bromide as appropriate... 

Nantokite, see Copper(I) chloride Natron, see Sodium carbonate Naumannite, see Silver selenide Neutral verdigris, see Copper(H) acetate Nitre (niter), see Potassium nitrate Nitric oxide, see Nitrogen(II) oxide Nitrobarite, see Barium nitrate Nitromagnesite, see Magnesium nitrate 6-water Nitroprusside, see Sodium pentacyanonitrosylfer-rate(II) 2-water... 

Iodoform Acetone, lithium, mercury(II) oxide, mercury(I) chloride, silver nitrate... 

There are three general types of radiopharmaceuticals elemental radionucHdes or simple compounds, radionucHde complexes, and radiolabeled biologically active molecules. Among the first type are radionucHdes in their elemental form such as Kr and Xe or Xe, and simple aqueous radionucHde solutions such as or I-iodide, Tl-thaUous chloride, Rb-mbidium(I) chloride [14391-63-0] Sr-strontium(II) chloride, and Tc-pertechnetate. These radiopharmaceuticals are either used as obtained from the manufacturer in a unit dose, ie, one dose for one patient, or dispensed at the hospital from a stock solution that is obtained as needed from a chromatographic generator provided by the manufacturer. 

Production and Economic Aspects. Thallium is obtained commercially as a by-product in the roasting of zinc, copper, and lead ores. The thallium is collected in the flue dust in the form of oxide or sulfate with other by-product metals, eg, cadmium, indium, germanium, selenium, and tellurium. The thallium content of the flue dust is low and further enrichment steps are required. If the thallium compounds present are soluble, ie, as oxides or sulfates, direct leaching with water or dilute acid separates them from the other insoluble metals. Otherwise, the thallium compound is solubilized with oxidizing roasts, by sulfatization, or by treatment with alkaU. The thallium precipitates from these solutions as thaUium(I) chloride [7791 -12-0]. Electrolysis of the thaUium(I) sulfate [7446-18-6] solution affords thallium metal in high purity (5,6). The sulfate solution must be acidified with sulfuric acid to avoid cathodic separation of zinc and anodic deposition of thaUium(III) oxide [1314-32-5]. The metal deposited on the cathode is removed, kneaded into lumps, and dried. It is then compressed into blocks, melted under hydrogen, and cast into sticks. 

Nucleophilic Reactions. Useful nucleophilic substitutions of halothiophenes are readily achieved in copper-mediated reactions. Of particular note is the ready conversion of 3-bromoderivatives to the corresponding 3-chloroderivatives with copper(I)chloride in hot /V, /V- dim ethyl form am i de (26). High yields of alkoxythiophenes are obtained from bromo- and iodothiophenes on reaction with sodium alkoxide in the appropriate alcohol, and catalyzed by copper(II) oxide, a trace of potassium iodide, and in more recent years a phase-transfer catalyst (27). 

Using a number of other aldehydes, more compHcated products result. Stmcture (2) was also found to react with alkynes in the presence of copper(I) chloride to give furans ... 

Pure monochlorotoluene isomers are prepared by dia2oti2ation of the corresponding toluidine isomers followed by reaction with copper(I) chloride (Sandmeyer reaction). This is the preferred method of obtaining y -chlorotoluene. 

Thin films of photochromic glass containing silver haUde have been produced by simultaneous vacuum deposition of siUcon monoxide, lead siUcate, aluminum chloride, copper (I) chloride, and silver haUdes (9). Again, heat treatment (120°C for several hours) after vacuum deposition results in the formation of photochromic silver haUde crystaUites. Photochemical darkening and thermal fade rates are much slower than those of the standard dispersed systems. 

Copper(I) chloride is insoluble to slightly soluble in water. SolubiUty values between 0.001 and 0.1 g/L have been reported. Hot water hydrolyzes the material to copper(I) oxide. CuCl is insoluble in dilute sulfuric and nitric acids, but forms solutions of complex compounds with hydrochloric acid, ammonia, and alkaU haUde. Copper(I) chloride is fairly stable in air at relative humidities of less than 50%, but quickly decomposes in the presence of air and moisture. 

Copper(II) oxychloride [1332-65-6], Cu2Cl(OH)2, is found in nature as the green hexagonal paratacamite [12186-OOA] or rhombic atacamite [1306-85-0]. It is usually precipitated by air oxidation of a concentrated sodium chloride solution of copper(I) chloride (13—15). Often the solution is circulated through a packed tower of copper metal, heated to 60—90°C, and aerated. 

---