Reactions with inorganic chlorides

A convenient synthesis of organochlorosilanes from organosilanes is achieved by reaction with inorganic chlorides of Hg, Pt, V, Cr, Mo, Pd, Se, Bi, Fe, Sn, Cu, and even C. The last compounds, tin tetrachloride, copper(II) chloride, and, under catalytic conditions, carbon tetrachloride (117,118), are most widely used. 

REACTIONS OF CARBON MONOXIDE WITH INORGANIC CHLORIDES... 

Dioxins and dibenzofurans form catalytically from pentachlorophenol wastes, chlorinated phenol precursors, and from nonchlorinated compounds by the reaction of phenol with inorganic chloride ion in the low-temperature region of the incinerator plant. Karasek and Dickson (1987) determined with optimum temperature range as 250-350°C (482-662°F) for the formation of dioxins from pentachlorophenol. Eklund et al. (1986) observed that the formation of these toxic compounds depended on the HCl concentration in the incinerator. Such formation is probably caused by phenol and HCl and may be controlled by injecting suitable alkaline sorbent along with the fuel. These compounds may also be formed from the carbon particulates in the incinerators. The concentrations of dioxins produced from pentachlorophenol were much higher than those produced from carbon (Dickson et al. 1988). In addition, carbon catalyzed the formation of... 

The high sodium ion concentration results in facile crystallisation of the sodium salt. This process of salting out with common salt may be used for recrystallisation, but sodium benzenesulphonate (and salts of other acids of comparable molecular weight) is so very soluble in water that the solution must be almost saturated with sodium chloride and consequently the product is likely to be contaminated with it. In such a case a pure product may be obtained by crystallisation from, or Soxhlet extraction with, absolute alcohol the sul-phonate is slightly soluble but the inorganic salts are almost insoluble. Very small amounts of sulphones are formed as by-products, but since these are insoluble in water, they separate when the reaction mixture is poured into water ... 

Chemical Properties. Thionyl chloride chemistry has been reviewed (169—173). Significant inorganic reactions of thionyl chloride include its reactions with sulfur trioxide to form pyrosulfuryl chloride and with hydrogen bromide to form thionyl bromide [507-16-4]. With many metal oxides it forms the corresponding metal chloride plus sulfur dioxide and therefore affords a convenient means for preparing anhydrous metal chlorides. 

Stannic and stannous chloride are best prepared by the reaction of chlorine with tin metal. Stannous salts are generally prepared by double decomposition reactions of stannous chloride, stannous oxide, or stannous hydroxide with the appropriate reagents. MetaUic stannates are prepared either by direct double decomposition or by fusion of stannic oxide with the desired metal hydroxide or carbonate. Approximately 80% of inorganic tin chemicals consumption is accounted for by tin chlorides and tin oxides. 

When heated with pyrocatechol [720-80-9] copper powder, and alcohoHc sodium hydroxide, carbon tetrachloride gives a blue color that changes to red on addition of hydrochloric acid. This color reaction is not produced by chloroform. Quantitative analysis of carbon tetrachloride may be done by first decomposing the sample free of organic and inorganic chlorides, heating in a sealed tube with alcohoHc potash, and subsequently determining the potassium chloride formed as the silver haHde. The Zeiss interference refractometer has been used to determine the concentration of carbon tetrachloride vapor in air (36). 

Materials of Construction. GeneraHy, carbon steel is satisfactory as a material of construction when handling propylene, chlorine, HCl, and chlorinated hydrocarbons at low temperatures (below 100°C) in the absence of water. Nickel-based aHoys are chiefly used in the reaction area where resistance to chlorine and HCl at elevated temperatures is required (39). Elastomer-lined equipment, usuaHy PTFE or Kynar, is typicaHy used when water and HCl or chlorine are present together, such as adsorption of HCl in water, since corrosion of most metals is excessive. Stainless steels are to be avoided in locations exposed to inorganic chlorides, as stainless steels can be subject to chloride stress-corrosion cracking. Contact with aluminum should be avoided under aH circumstances because of potential undesirable reactivity problems. 

Double Decomposition. In the double decomposition reaction, an inorganic metal salt such as a sulfate, chloride, acetate, or nitrate reacts with the sodium salt of the carboxyUc acid ia a hot aqueous solution. The metal soap precipitate is filtered, washed, dried, and milled. 

These last named materials may be considered as derivatives of the inorganic rubber, polyphosphonitrilic chloride, discovered by Stokes in 1895. This was prepared by the reaction of phosphorus pentachloride with ammonium chloride as follows ... 

Inorganic Chlorides/Halides — These metallic salts are formed from the reaction of a weak base with the strong acid HCl. Salts such as these dissolve in water to produce a markedly acidic solution. This is exemplified by aluminum chloride, which is corrosive due to the acidity resulting from the hydrolysis that produces aluminum and chlorine ions. Anhydrous AICI3 hydrolyzes violently when contacted by water. 

Industrial use of HCl gas for the manufacture of inorganic chemicals includes the preparation of anhydrous NH4CI by direct reaction with NH3 and the synthesis of anhydrous metal chlorides by reaction with appropriate carbides, nitrides, oxides or even the free metals themselves, e,g, ... 

The solvent system N2O4/DMF has been employed for the preparation of inorganic esters, e.g., phosphates and sulfates [221] as well as organic esters. The latter products were obtained by reacting the polymer with acyl chlorides, or acid anhydrides in the presence of a pyridine base. The nitrite ester formed has been successfully trans-esterified by the reaction with RCOCl... 

---