Indium solubilities

C22H23N3O9. An organic reagent used for the detection and estimation of aluminium. It is a brownish-red powder, soluble in water which gives a red lake with aluminium which can be estimated colorimetrically. It can also be used for detecting scandium and indium. 

Halides. Indium trichloride [10025-83-8] InCl, can be made by heating indium in excess chlorine or by chlorinating lower chlorides. It is a white crystalline soHd, deUquescent, soluble in water, and has a high vapor pressure. InCl forms chloroindates, double salts with chlorides of alkaLi metals, and organic bases. 

Mono-, di-, and trivalent bromides and iodides may be made by methods similar to the chlorides. The lower valence salts also disproportionate in water. Indium trifluoride [7783-52-0] InF., is sparingly soluble in water. It forms an ammonium double salt, SNH F TnF. [15273-84-4] which decomposes on heating to indium nitride [25617-98-5] InN. 

Sulfates. Indium metal and its oxides dissolve in warm sulfuric acid to give a solution of the trisulfate [13464-82-9], In2(S0 2- It is a white, crystalline, deUquescent soHd, readily soluble in water that forms double salts with alkaLi sulfates and some organic substituted ammonium bases. Concentration of the acidified trisulfate solution produces indium acid sulfate crystal [57344-73-7], In(HS0 2> other reaction conditions give basic sulfates. 

Other Salts. Indium nitrate trihydrate [13770-61 -1], In(N02)3 3H20, is a soluble salt prepared by dissolution of the metal or oxide in nitric acid. Indium phosphate [14693-82-4], InPO, is precipitated by adding phosphate ions to a solution of an indium salt. It is soluble in water. 

Binary Compounds. The fluorides of indium are IrF [23370-59-4] IrF [37501-24-9] the tetrameric pentafluoride (IiF ) [14568-19-5], and JIrFg [7789-75-7]. Chlorides of indium include IrCl, which exists in anhydrous [10025-83-9] a- and p-forms, and as a soluble hydrate [14996-61-3], and IrCl [10025-97-5], Other haUdes include IrBr [10049-24-8], which is insoluble, and the soluble tetrahydrate IrBr -4H20 IrBr [7789-64-2]-, and Irl [7790-41-2], Iridium forms indium dioxide [12030-49-8], a poorly characteri2ed sesquioxide, 11203 [1312-46-5]-, and the hydroxides, Ir(OH)3 [54968-01-3] and Ir(OH) [25141-14-4], Other binary iridium compounds include the sulfides, IrS [12136-40-2], F2S3 [12136-42-4], IrS2 [12030-51 -2], and IrS3 [12030-52-3], as well as various selenides and teUurides. 

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. 

Unlike boron, aluminum, gallium, and indium, thallium exists in both stable univalent (thaHous) and trivalent (thaUic) forms. There are numerous thaHous compounds, which are usually more stable than the corresponding thaUic compounds. The thaUium(I) ion resembles the alkaU metal ions and the silver ion in properties. In this respect, it forms a soluble, strongly basic hydroxide and a soluble carbonate, oxide, and cyanide like the alkaU metal ions. However, like the silver ion, it forms a very soluble fluoride, but the other haUdes are insoluble. Thallium (ITT) ion resembles aluminum, gallium, and indium ions in properties. 

The solutions used are generally highly concentrated, except in the case of the precious metals (for reasons of expense) and when zinc and cadmium are deposited from cyanide solutions, since soluble anodes are employed in the cases of these two metals. Proprietary solutions are available, particularly for such difficult metals as chromium, rhodium and indium, and it is advisable to use them. 

Tris(0-ethyl dithiocarbonato)chromium(III) is obtained as a dark blue crystalline powder which decomposes at 100 to 140°. The indium(III) ethylxanthate complex forms small colorless crystals which decompose at 130 to 150°.16,17 The cobalt (III) ethylxanthate complex is isolated as a dark green crystalline powder whose decomposition temperature determined by use of a thermal balance is 135 to 137° (lit. value, 117° 2 118 to 119°8). These compounds decompose slowly in air and more rapidly when heated in solution. The tripositive chromium, indium, and cobalt complexes are insoluble in water but are soluble in many organic solvents (Table T). 

TABLE I Solubilities of Tris(0-ethyl dithiocarbonato) Complexes of Chromium(III), Indium(III), and Cobalt(III) in Organic Solvents at 25°... 

Singh et al. (2006) also used cycloaddition to prepare carbon nanotubes containing indium labeled diethylenetriamine pentaacetic acid (DTPA) derivatives (Figure 15.17). In the initial modification, a SWNT was derivatized to contain a primary amine at the end of a short PEG spacer. The resultant water-soluble nanotube then was reacted with DTPA to create a metal chelating group at the end of the chain. Subsequent loading of the chelate with mIn created a radionuclide-SWNT complex for in vivo biodistribution studies. 

Fig. 25. Structure of water-soluble indium porphyrins with rele vance to inIn SPECT.

There is a large temperature variation of solubility for the tris-dmpp complex of indium (143) but a much smaller variation for tris(malto-lato)aluminum (242) in aqueous solution. The solubility of the former increases by a factor of 3.5, of the latter by only 1.3 times, on raising the temperature from 298 to 310 K, i.e., from the standard 25°C to the physiological 37°C. The enthalpy of solution of Al(malt)3 in water is 23kJmol , but is medium-dependent, rising to 56kJmol in 80% methanol. 

Indium chloride inorg chem InClj Hygroscopic white powder, soluble in water and alcohol. in-de-om kl6r,Td ... 

Surprisingly, there are only a few catalysts known capable of hydrogenating ketones in fully or largely aqueous systems. For example, most of the water-soluble rhodium, mthenium and indium phosphine complexes preferentially hydrogenate the C=C bonds in unsaturated ketones, as does the solvated ion pair formed from aqueous rhodium trichloride and Aliquat-336 [206]. 

Indium has one odd characteristic in that in the form of a sheet, like the metal tin, it will emit a shrieking sound when bent rapidly. Indium has some of the characteristics of other metals near it in the periodic table and may be thought of as an extension of the second series of the transition elements. Although it is corrosion-resistant at room temperature, it will oxidi2e at higher temperatures. It is soluble in acids, but not in alkalis or hot water. 

The described preparation of Inl is a modification of a 3-step literature procedure in which indium shot is hammered into indium foil and heated with iodine to form Inig/ The Inlg is then heated with excess indium foil to form 10314 (3 complex of Inl[lnl3]).ln a third step, the Iri2l4 is treated with diethyl ether whereupon it disproportionates to insoluble Inl and soluble Inij etherate that are separated by filtration. 

After 2xh hours the gas flow is terminated and the power supply is disconnected. The layer of brown oil formed in the bottom of the vessel contains no indium and can be rejected. The supernatant is carefully removed to a 100-mL round-bottomed flask, and the solvent is removed by pumping in vacuo at room temperature until the volume is reduced to about 15 mL. The resultant white solid is collected and washed quickly with several small volumes of diethyl ether although indium(III) chloride is soluble in diethyl ether, the rate of dissolution is fairly slow, and the losses in this washing are tolerable. The collection and washing operations are carried out under dry nitrogen. Yield 0.23 g (26%, based on indium consumed). Anal. Calcd. for InCU In, 51.9 Cl 48.1. Found In (atomic absorption), 51.9 Cl (silver nitrate-potassium thiocyanate titration) 48.8. 

Tris(dimethyl sulfoxide)indium(III) chloride is a white crystalline nonhygro-scopic compound, soluble in alcohols, ethyl acetate, and nitromethane. Decomposition occurs at 130°. The infrared spectrum and the results of thermal stability studies have been reported.6 The presence of dmso can be verified from the infrared spectrum,6 which shows C—H vibrations, and =0 at 945, 960, and 995 cm. ... 

Indium tribromide is a white hygroscopic crystalline solid, mp 436° the vibrational spectrum suggests that each indium is surrounded octahedrally by six bromine atoms.4,s The solubility in organic solvents is similar to that for indium(IIl) chloride (see above). 

Renz 4 describes an additive compound of indium trichloride and pyridine, tripyridino-indium trichloride, [In(C5H5N)3]Cl3, which is prepared by adding pyridine to a solution of indium trichloride in alcohol. After standing for a short time, small needle-shaped crystals separate of melting-point 253° C. The compound is not hygroscopic like indium chloride, is somewhat sparingly soluble in alcohol, and is insoluble in ether. It decomposes on warming with water with formation of indium hydroxide, In(OH)3. Aluminium trichloride and iron trichloride form similar addition products. 

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