Sulfides also

Other sulfur compounds such as thiourea, ammonium dithiocarbamate, or hydrogen sulfide also lead to 2-mercaptothiazoles. Thus thiourea has been used in the syntheses of 4,5-dimethyl (369) and 4-aryl-2-mercapto-thiazoles (Table 11-30) (519). The reactions were carried out by condensing the ia -thiocyanatoketones with thiourea in alcohol and water acidified with hydrochloric acid. By this procedure, 4-aryl-2-mercaptothiazoles were obtained in yields of 40 to 80% with bis-(4-aryl-2-thiazolyl) sulfides as by-products (519). These latter products (194) have also been observed as a result of the action of thiourea on 2-chloro-4-arylthiazole under the same experimental conditions. They can be separated from 2-mercaptothiazoles because of their different degrees of solubility in sodium hydroxide solution at 5%. In this medium bis-(4-phenyl-2-thiazolyl)sulfide is... 

Sulfurization of unsaturated compounds ia the presence of hydrogen sulfide also affords polysulfides (9). It is postulated that this reaction forms the mercaptan in situ which then further reacts to form the polysulfide (see Sulfurcompounds). 

If tin and sulfur are heated, a vigorous reaction takes place with the formation of tin sulfides. At 100—400°C, hydrogen sulfide reacts with tin, forming stannous sulfide however, at ordinary temperatures no reaction occurs. Stannous sulfide also forms from the reaction of tin with an aqueous solution of sulfur dioxide. Molten tin reacts with phosphoms, forming a phosphide. Aqueous solutions of the hydroxides and carbonates of sodium and potassium, especially when warm, attack tin. Stannates are produced by the action of strong sodium hydroxide and potassium hydroxide solutions on tin. Oxidizing agents, eg, sodium or potassium nitrate or nitrite, are used to prevent the formation of stannites and to promote the reactions. 

Hydrogen sulfide and carbon react at 900°C to give a 70% yield of carbon disulfide (102,103). A process for reaction of coke and hydrogen sulfide or sulfur in an electric-resistance-heated fluidized bed has been demonstrated on a laboratory scale (104). Hydrogen sulfide also forms carbon disulfide in reactions with carbon monoxide at 600—1125°C (105) or carbon dioxide at 350—450°C in the presence of catalysts (106). 

Hydrogen sulfide also is formed, and this instantly reacts with iron and steel to form thin deposits of black ferrous sulfide in the superheater tubes ... 

Similar sulfur substitution, as in a fluoromethyl sulfide, also leads to deshielding, but somewhat less than for the analogous ether. 

Sparking of mixtures with ammonia or hydrogen causes violent explosions, and with steam, feeble ones [1]. Mixtures with ethylene, methane and hydrogen sulfide (also carbon monoxide) explode on sparking [2],... 

It heats and may ignite in contact with limited amounts of water, hydrogen sulfide also being evolved. 

Two of the species, Thiobacillus concretivorus and Thiobacillus neapolitanus, are, in addition to sulfide, also able to use thiosulfate and elemental sulfur as energy sources. 

O Chlorine gas reacts with aqueous hydrogen sulfide (also known as hydrosulfuric acid) to form elemental sulfur and hydrochloric acid. Cl2(g) + H2S(aq) S(s) + 2HCl(aq)... 

Cadmium sulfide also may be obtained by treatment of sodium or other alkali metal sulfide solution with that of a soluble cadmium salt. The compound also may be prepared by heating a mixture of cadmium or its oxide with sulfur at 800°C or by the reaction of H2S with cadmium vapor at 800°C. 

Calcium sulfide occurs in nature as the mineral oldhamite. It has several applications. The luminous calcium sulfide is used in phosphors, luminous paints and varnishes. Calcium sulfide also is used as an additive to lubricants and as a flotation agent in ore extraction. 

Hydrogen sulfide also reacts with many types of organic substances. Reaction with methanol at high temperatures in the presence of an acidic catalyst yields methanethiol and dimethylsulfide ... 

Lead sulfide also undergoes various oxidation reactions at elevated temperatures that occur in a reverberatory furnace, during the production of lead from galena. Sulfur dioxide and lead sulfate are formed as intermediate products. Some typical reactions are as follows ... 

The red sulfide also may be made from black sulfide by heating in a concentrated solution of alkaline polysulfide. The shade of pigment varies with temperature, reaction time, and concentration of the black sulfide. 

Nickel sulfide also can be prepared by reacting nickel powder with molten sulfur. 

Sodium sulfide also is produced when the metal is heated with carbon disulfide. The reaction is violent ... 

Sb sulfide also seems to fulfil the role of a neutralizer and preservative for phosphorus. 

The aubrites are the most reduced achondrites (Keil et al., 1989). Their silicates are essentially free of iron, and they contain minor metallic iron. A variety of unusual sulfides of calcium, chromium, manganese, titanium, and sodium - all usually lithophile elements -occur in aubrites. These unusual sulfides also characterize the highly reduced enstatite chondrites, which may have been precursors for these rocks. 

Genotoxic Effects and Carcinogenicity. Tests for damages of the DNA [3.117] and cell transformation caused by crystalline cadmium sulfide were positive [3.118]. Cadmium sulfide also proved to be carcinogenic by intraperitoneal and after intratracheal administration [3.119]. The significance of such animal studies is being controversially discussed by toxicologists. 

The alkyl sulfides have the general formula RSR. Aklyl sulfides also are called thio ethers or mono sulfides. Alkyl sulfides form the chief ingredient in many of the spices used in cooking. For instance, allylsulfide is a chief constituent of garlic. 

The reaction of an osmium carbene cluster containing the cyclic carbene ligand = C(CH=CH)2C(Ph)H which is side on bound to a nonacarbo-nyltriosmium unit with either elemental sulfur/NEt3 or cyclohexene sulfide also afforded a rf-thioketone complex.184... 

Iron frequently has been postulated to be an important electron acceptor for oxidation of sulfide (58, 84,119, 142, 152). Experimental and theoretical studies have demonstrated that Fe(III) will oxidize pyrite (153-157). Reductive dissolution of iron oxides by sulfide also is well documented. Progressive depletion of iron oxides often is coincident with increases in iron sulfides in marine sediments (94, 158, 159). Low concentrations of sulfide even in zones of rapid sulfide formation were attributed to reactions with iron oxides (94). Pyzik and Sommer (160) and Rickard (161) studied the kinetics of goethite reduction by sulfide thiosulfate and elemental S were the oxidized S species identified. Recent investigations of reductive dissolution of hematite and lepidocrocite found polysulfides, thiosulfate, sulfite, and sulfate as end products (162, 163). 

Sulfide. Sulfide appears in the water column of Lake Greifen only at the end of stagnation time and in the deepest water layers. This distribution indicated the biological reduction of sulfate in sediments. The reactions involved in the sulfur cycle are described in ref. 65. The occurrence of sulfide indicates a very low pe (p < 0) sulfide is an efficient reductant for many elements, including Fe(III), Mn(IV), As(V), and Cr(VI). The occurrence of sulfide also implies the possible precipitation of solid sulfide phases of various elements and the formation of dissolved complexes (21-23). 

Be(Pc) and Mg(Pc) are obtained by the condensation reaction of phthalonitrile in the presence of metallic Be and Mg respectively.197,198 They form very stable complexes with water. Mg(Pc)(OH2) is square pyramidal and the magnesium atom is displaced out of the N4 plane by 0.5 A with an Mg—distance of 2.04 A. They lose the water on sublimation. Amines, alcohols, ketones, thiols and sulfides also coordinate to Mg(Pc). Ca(Pc) and Ba(Pc) are obtained from phthalonitrile and the metal oxide.197,199... 

Quite puzzingly, thiols are reported14b to be unreactive under Pfitzner-Moffatt conditions, while this being one of the few oxidation methods for alcohols compatible with this functionality. Sulfides also resist the action of Pfitzner-Moffatt oxidations.42,43... 

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