Lead bromide, solubility product

Lead tri-n-butyl chloride is obtained from magnesium butyl iodide, and lead chloride, the product being treated with hydrogen chloride as above. It forms colourless, flat needles which melt to a clear liquid at 109° to 110° C., and have a similar solubility to the propyl compound. The hydroxide is prepared by dissolving the chloride in aqueous alcohol and shaking with silver oxide. The solution in water ha an alkaline reaction, and absorbs carbon dioxide from the air. When treated with hydrogen bromide a white precipitate of lead iri-n-butyl bromide separates, which may be recrystallised from ether or chloroform. 

Lead diphenyl di-a-naphthyl, Pb(C6ll5)2(CioH7)2. This is obtained as a snow-white, granular, crystalline powder by the interaction of lead diphenyl dibromide and magnesium a-naphth d bromide. The product melts at 197° C., lead separating at a higher temperature, and it is soluble in ether, benzene, or hot alcohol. It reacts with thallic chloride according to the equation ... 

Lead is not generally attacked rapidly by salt solutions (especially the salts of the acids to which it is resistant). The action of nitrates and salts such as potassium and sodium chloride may be rapid. In potassium chloride the corrosion rate increases with concentration to a maximum in 0.05m solution, decreases with a higher concentration, and increases again in 2m solution. Only loosely adherent deposits are formed. In potassium bromide adherent deposits are formed, and the corrosion rate increases with concentration. The attack in potassium iodide is slow in concentrations up to 0.1m but in concentrated solutions rapid attack occurs, probably owing to the formation of soluble KPblj. In dilute potassium nitrate solutions (0.001 m and below) the corrosion product is yellow and is probably a mixture of Pb(OH)2 and PbO, which is poorly adherent. At higher concentrations the corrosion product is more adherent and corrosion is somewhat reduced Details of the corrosion behaviour of lead in various solutions of salts are given in Figure 4.16. 

Miscellaneous Reactions of Phosphines.- The role of chiral phosphines as ligands in the catalysis of reactions leading to the formation of chiral products has been reviewed.1111 A procedure for the determination of the enantiomeric excess in chiral phosphines has been developed, based on 13C n.m.r. studies of the diastereoisomeric complexes formed by phosphines with the chiral pinenyl nickel bromide complex. 111 Studies of the sulphonation of triphenylphosphine and of chiral arylphosphines have been reported in attempts to prepare water soluble ligands which aid... 

Cross-linked polystyrene can be directly brominated in carbon tetrachloride using bromine in the presence of Lewis acids (Experimental Procedure 6.2 [55-58]). Thal-lium(III) acetate is a particularly suitable catalyst for this reaction [59]. Harsher bro-mination conditions should be avoided, because these can lead to decomposition of the polymer. Considering that isopropylbenzene is dealkylated when treated with bromine to yield hexabromobenzene [60], the expected products of the extensive bromi-nation of cross-linked polystyrene would be soluble poly(vinyl bromide) and hexabromobenzene. In fact, if the bromination of cross-linked polystyrene is attempted using bromine in acetic acid, the polymer dissolves and apparently depolymerizes [61]. 

Lead triphenyl iodide. —If the mother-liquors of the above bromide be treated with potassium iodide, and the product obtained crystallised from water, the iodide separates in pale yellow prisms, which sinter at 189 C. and melt sharply at 142 C. to a canary yellow liquid, which soon deposits lead iodide. It is difficultly soluble in liot methyl alcohol, and insoluble in water, and is distinguished from all the other lead aryl or alkyl iodides by its stability. It does not appear to yield an oxide with alcoholic sodium or potassium hydroxide, but a white precipitate is thrown down, this yielding lead triphenyl chloride with 50 per cent, hydrochloric acid. 

The 1,5,2,4-dioxazadiazinedione system (35) has been prepared. However, these compounds decompose very readily. Thermal decomposition leads to carbon dioxide loss with the formation of isocyanates and nitrosoalkanes (Equation (1)). The compounds are stable to water, but are attacked by organic soluble nucleophiles, and reagents such as phenylmagnesium bromide, to yield products which arise from attack of the nucleophile at the carbonate carbonyl, followed by fragmentation (Equation (1)). Catalytic reduction of (35) leads to ureas <86JOC3355>. 

Beilstein Handbook Reference) AI3-52311 BRN 0969143 CCRIS 939 Dibromomethane EINECS 200-824-2 HSDB 1334 Methane, dibromo- Methylene bromide Methylene dibromide NSC 7293 RCRA waste number U068 UN26M. Used in the production of leaded gasoline, as a fumigant for stored products and as a nematocide. Also used in the manufacture of fire retardent chemicals. Dense, mobile liquid mp = -52.5 bp = 97 d = 2.4969 soluble in organic solvents, slightly soluble in H2O. 

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