Reactions with lead sulfides

Acyl chlorides react with epoxides in the presence of a Eu(dpm)3 catalyst or a YCp2Cl catalyst (where Cp is cyclopentadienyl) to give chloro esters. A related reaction with epi-sulfides leads to 2-chlorothio-esters. Aziridines have been opened with MgBr2 to give 2-haloamides in a related reaction. 

Reaction with hydrogen sulfide forms black precipitate of lead sulfide, PbS. A paper soaked with lead acetate solution turns black on exposure to H2S, a test often used to detect sulfide. 

Alternatives to carboxylation of the dianions include the reaction with carbonyl sulfide leading to the thiolacid (335) which spontaneously cyclizes (Scheme 100) (69T2687). 

Certain compounds, such as those bearing thiol groups (—SH), facilitate chain transfer. Thiol groups, leading to higher grafting yields, can be introduced into the cellulose by reaction with ethylene sulfide ... 

In a variation of this procedure, the lead oxide can be mixed with lead sulfide and heated. The reaction that takes place results in the formation of lead metal and sulfiir dioxide gas. 

The second reaction cannot be performed in an iron crucible, because iron reacts rapidly with lead sulfide at a red heat to form iron sulfide and lead. 

Herein is described a novel method for preparing core-shell (c-s) particles of polystyrene coated with lead sulfide nanocrystals. The reaction is performed at room ten erature, in an aqueous bath, firom lead acetate and thioacetamide in the presence of ethylenediamine. 

Steel pipes buried in anaerobic soils such as clay sometimes exhibit a pitting type corrosion that leads to local penetration of the pipe wall. The corrosion products contain iron sulfide, which can be detected by adding a drop of hydrochloric acid the reaction with iron sulfide releases H2S with has the typical smell of rotten eggs. The described corrosive attack is due to the presence of SRB at the surface, which transform sulfate, a soil constituent, into sulfide. The reaction mechanism, although... 

Reaction of an alkene with ozone leads to a 1,2,3-trioxolane, which rearranges to a 1,2,4-trioxolane (an ozonide). Subsequent treatment with hydrogen peroxide or with dimethyl sulfide leads to an aldehyde, ketone, or carboxylic acid product. When an ozonide contains a C-H unit, oxidation with hydrogen peroxide leads to a carboxylic acid, but reaction with dimethyl sulfide leads to an aldehyde 51, 52, 53, 54, 78,82,83,117. 

Most of the early development attempts centred on the use of chloride systems that relied on the reaction of lead sulfide with chlorine to produce lead chloride and elemental sulfur, followed by electrolysis of the lead chloride to produce lead metal and chlorine for recycle. 

A second approach to eliminate the two-step discharge was through the use of silver plumbate as a cathode additive material. Silver plumbate cathode material was prepared by reacting an excess of divalent silver oxide powder with lead sulfide (PbS) in a hot alkaline solution. The product of the reaction is a mixture of remaining divalent silver oxide (AgO), monovalent silver oxide (Ag20), and silver plumbate (Ag5Pb20g). The sulfur is oxidized to the sulfate and is washed from the reaction product ... 

Copper is frequently a main impurity ia blast-furnace charges, and its limited solubiUty ia molten lead as copper sulfide requires that the excess be removed by chemical reaction with components of the charge. For this reason enough sulfur is left ia the siater to form a copper sulfide matte layer having a specific gravity of 5.2. 

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