Hydrogen aluminum tetrachloride

Cl—Al Cly) intermediate or a carbocation C AICI4 This intermediate electrophilically attacks the benzene ring to generate a benzenonium ion intermediate which gives alkylated benzene through deprotonation by aluminum tetrachloride anion. Finally the hydrogen aluminum tetrachloride complex affords aluminum chloride and hydrogen chloride gas. This aluminum chloride is recycled in the catalytic cycle of alkylation. 

Recent work (Brown and Pearsall, 15) has indicated that while hydrogen aluminum tetrachloride is nonexistent, interaction of aluminum chloride and hydrogen chloride does occur in the presence of substances (such as benzene and presumably, olefins) to which basic properties may be ascribed. It may be concluded that while hydrogen aluminum tetrachloride is an unstable acid, its esters are fairly stable. Further evidence in support of the hypothesis that metal halides cause the ionization of alkyl halides (the products of the addition of the hydrogen halide promoters to the olefins) is found in the fact that exchange of radioactive chlorine atoms for ordinary chlorine atoms occurs when ferf-butyl chloride is treated with aluminum chloride containing radioactive chlorine atoms the hydrogen chloride which is evolved is radioactive (Fair-brother, 16). 

The probable function of hydrogen halides as promoters for the metal halides and boron fluoride in the alkylation of isoparaffins seems to be to initiate and maintain the formation of f-alkyl halide by the reaction of step 1. Also, it may convert the metal halide to the more active form, such as, for example, hydrogen aluminum tetrachloride or an ester thereof. 

The formation of hydrogen aluminum tetrachloride, as assumed in step 1, does not seem plausible in view of the reported recent work (Brown and Pearsall, 18) which indicated that this compound is nonexistent. The interaction of aluminum chloride and hydrogen chloride does presumably occur in the presence of olefins. 

Unlike uranium pentaehloride, which is thermally unstable, protactinium pentachloride sublimes unchanged above 180°C in vacuo. It is a yellow, moisture-sensitive solid which is slightly soluble in benzene, tetrahydrofuran, and carbon tetrachloride. Visible absorption speetra have been reeorded for solutions in the last two solvents and in aleohol (110). Reactions with hydrogen, aluminum, oxygen, and silicon tetra-iodide are discussed below. It is unaffected by carbon monoxide at 350°C in a sealed tube. 

In this reaction, the catalyst is regenerated when hydrogen ion reacts with the aluminum tetrachloride anion. 

In the same vein, Gatterman showed that carbon monoxide (CO) and hydrogen chloride (HCl) would react with benzene (CeH ) in the presence of aluminum trichloride (AICI3) at high pressure so as to substitute an dehyde functional group for a hydrogen. The actual electrophile attacked by the aromatic ring may be the acylium ion shown in Scheme 6.89 complexed with the aluminum tetrachloride anion. 

Hydrogen iodide iodinates triaLkylsilanes in good yield in boiling carbon tetrachloride with no aluminum haUde present (116). This can perhaps be explained on the basis that some free iodine is always present in equiUbrium with hydrogen iodide. 

Titanium trichloride is almost always prepared by the reduction of TiCl, most commonly by hydrogen. Other reduciag agents iaclude titanium, aluminum, and 2iac. Reduction begias at temperatures of ca 500°C and under these conditions a-TiCl is formed. The product is cooled quickly to below 450°C to avoid disproportionation to the di- and tetrachlorides. P-TiCl is prepared by the reduction of titanium tetrachloride with aluminum alkyls at low (80°C) temperatures whereas y-TiCl is formed if titanium tetrachloride reacts with aluminum alkyls at 150—200°C. At ca 250°C, the P-form converts to d. d-TiCl is made by prolonged grinding of the d- or y-forms. 

Sihcon carbide is comparatively stable. The only violent reaction occurs when SiC is heated with a mixture of potassium dichromate and lead chromate. Chemical reactions do, however, take place between sihcon carbide and a variety of compounds at relatively high temperatures. Sodium sihcate attacks SiC above 1300°C, and SiC reacts with calcium and magnesium oxides above 1000°C and with copper oxide at 800°C to form the metal sihcide. Sihcon carbide decomposes in fused alkahes such as potassium chromate or sodium chromate and in fused borax or cryohte, and reacts with carbon dioxide, hydrogen, ak, and steam. Sihcon carbide, resistant to chlorine below 700°C, reacts to form carbon and sihcon tetrachloride at high temperature. SiC dissociates in molten kon and the sihcon reacts with oxides present in the melt, a reaction of use in the metallurgy of kon and steel (qv). The dense, self-bonded type of SiC has good resistance to aluminum up to about 800°C, to bismuth and zinc at 600°C, and to tin up to 400°C a new sihcon nitride-bonded type exhibits improved resistance to cryohte. 

When treated with aluminum bromide at 100°C, carbon tetrachloride is converted to carbon tetrabromide [558-13-4], reaction with calcium iodide, Cal2, at 75°C gives carbon tetraiodide [507-25-5]. With concentrated hydroiodic acid at 130°C, iodoform [75-47-8], CHI, is produced. Carbon tetrachloride is unaffected by gaseous fluorine at ordinary temperatures. Replacement of its chlorine by fluorine is brought about by reaction with hydrogen fluoride at a... 

The reinforcing fibers are usually CVD SiC or modified aluminum oxide. A common matrix material is SiC deposited by chemical-vapor infiltration (CVI) (see Ch. 5). The CVD reaction is based on the decomposition of methyl-trichlorosilane at 1200°C. Densities approaching 90% are reported.b l Another common matrix material is Si3N4 which is deposited by isothermal CVI using the reaction of ammonia and silicon tetrachloride in hydrogen at 1100-1300°C and a total pressure of 5 torr.l" " ] The energy of fracture of such a composite is considerably higher than that of unreinforced hot-pressed silicon nitride. 

C03-0063. Which of the following compounds are ionic Write the formula of each compound, (a) hydrogen fluoride (b) calcium fluoride (c) aluminum sulfate (d) ammonium sulfide (e) sulfur dioxide and (f) carbon tetrachloride. 

Alkali metals, finely divided aluminum and magnesium particles, hydrazine, diborane, metal hydrides, and hydrogen are strong reducing agents [35]. An example of a significant problem is the possible explosive reaction between light metals and carbon tetrachloride which is itself a stable compound [57]. 

Neptunium forms a number of halides in various oxidation states. These include tri-, tetra- and hexafluorides of compositions NpFs, NpF4, and NpFe, respectively trichloride, NpCF and tetrachloride, NpCh tribromide, NpBrs and the triiodide NpN. Neptunium fluorides are formed by heating neptunium dioxide at elevated temperatures with fluorine in the presence of hydrogen fluoride. The tetrachloride, NpCh is obtained similarly by heating the dioxide with carbon tetrachloride vapor at temperatures above 500°C. Neptunium tribromide and triiodide are prepared by heating the dioxide in a sealed vessel at 400°C with aluminum bromide and aluminum iodide, respectively. 

Titanium trichloride may be prepared by reducing titanium tetrachloride with hydrogen at 600°C. The tetrachloride may alternatively be reduced with aluminum, zinc, magnesium, tin, or by electrolysis. 

Aluminum powder, Carbon tetrachloride Aluminum powder, Tetrachlorethylene CNTA, Hydrogen sulfide. Benzene, Lead 11 hydroxide Mercury-ll-nitrate, Sodium azide Mercury, Nitric acid. Alcohol Mercury, Nitric acid. Ethanol Ammonia, Mercury oxide. Nitric acid Nitric acid. Methylene diformamide. Acetic anhydride. Formic acid. Benzene... 

Sodium cyanide, Glacial acetic acid, Chlorine gas. Carbon tetrachloride Benzene, Aluminum chloride, 2-Chloroacetyl chloride. Hydrochloric acid. Sodium hydroxide. Methylene chloride. Calcium chloride. Hexanes Methanol, MalononitrUe, o-Chlorobenzaldehyde, Piperdine Tetrahydrofuran, Hydrogen chloride, Chloropicrin, Powdered tin Benzene, Arsenic trichloride. Aluminum chloride. Hexanes Acetone, Sulfuric acid. Chlorine, Calcium chloride Isopropylamine, Glyoxal, Diethyl ether Benzene, Pyridine, Diphenylamine, Arsenic trichloride Tetraethyl lead. Arsenic trichloride... 

MOLECULE, hi the traditional sense, a molecule is the smallest particle of a chemical substance capable of independent existence with retention of all its chemical properties. Molecules comprise one or more atoms which need not be of the same kind. Only the rare, or noble gases form single-atom or monatomic molecules. All other elements form bi-. Iri. quudrt-. etc. atomic molecules, e.g.. hydrogen. H ozone. O-, phosphorus. P4 and sulfur, Sx or hydrogen chloride. IICI sodium sullide. Na S. aluminum chloride, AlClu carbon tetrachloride. C CI. and so on. 

Aluminum chloride Potassium t-butoxide Hydrogen bromide Thionyl chloride Titanium tetrachloride Hydrogen chloride... 

Thus, the direct synthesis of phenylchlorosilanes produces a complex mixture, which, apart from phenyltrichlorosilane, diphenyldichlorosilane, phenyldichlorosilane and triphenylchlorosilane, also contains silicon tetrachloride, trichlorosilane, benzene, solid products (diphenyl and carbon) and a gaseous product (hydrogen). It also forms high-boiling polyolefines, which are part of tank residue and can deposit on contact mass, reducing its activity. It should be kept in mind that the production of phenylchlorosilanes requires silicon with a minimal impurity of aluminum, because the aluminum chloride formed contributes to the detachment of the phenyl group from phenylchlorosilanes at higher temperature. The harmful effect of aluminum chloride is counteracted by the addition of metal salts to contact mass, which form a nonvolatile and nonreactive complex with aluminum chloride. 

Oxo-2,3-dihydro-4//-benzotelIurin3 27.6 g (9.3 mmol) of 2-carboxyethyl phenyl tellurium and 15.6 g (10 mmol) of butyl dichloromethyl ether are heated in the presence ofzinc(II) chloride at 50°. After evolution of hydrogen chloride has ceased, 100 m/ of carbon tetrachloride and activated charcoal are added. The resultant mixture is filtered, the solvent is evaporated from the filtrate on a water bath, and the residue is dissolved in 150 ml of dichloromethane. The solution is cooled to — 70° and 15 g (12 mmol) of aluminum trichloride are added in small portions to the cold solution. The mixture is allowed to warm to — 5 over 30 min, hydrolyzed with ice/water, and extracted with diethyl ether. The ether layer is separated, washed with aqueous sodium carbonate solution, dried, and the solvent is evaporated. The residue is distilled under vacuum and the fraction boiling at 150°/0.8 torr is collected. The product is recrystallized from methanol yield 1.45 g (60%) m.p. 34°. 

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