Silver halide, isolation

Silver halides dissolve in excess halide (e.g. AgCl is a hundred times more soluble in 1 M HC1 than in water) forming complex ions AgX2 and AgX3 [53]. These isolated anions are not often found in the solid state thus M2AgI3 (M = K, Rb, NH4) have comer linked tetrahedra (Figure... 

Although CD seems to have been limited to chalcogenides (including oxides and hydroxides) and isolated cases of carbonates, silver halides, and elemental Se, it should be possible to deposit salts of other anions. There are a number of other anions that can be slowly and homogeneously generated. These are discussed in Chapter 3. 

The formation of these relatively stable complex salts explains the solubility of the silver halides in sodium thiosulphate solution and the value of such a solution for fixing photographic prints. In many cases the complex salts have been isolated in the solid state,10 for example,... 

The isolated silver atom formed in this reaction could take part in latent image formation either by diffusion to a latent sub-center or by thermal dissociation with the transfer of an electron to the conduction band. Hence, it is theoretically possible that the absorption of one photon by the silver halide results in two latent image silver atoms. Reduction centers larger than Ag2 could not contribute additional silver to the latent image in this way until their size had been decreased to two atoms by reaction with holes. 

Other transmetallation reactions of silver halides or their complexes with phosphine ligands (e.g. [AgIP(Bu-w)3]) with alkylhthium and alkylmagnesium reagents confirm the fleeting stability of the alkylsilver compounds. In each case the composition of the AgR intermediates has been derived from the analysis of the products formed in their thermal decomposition. So far, representatives of the class of simple alkylsilver complexes have not been isolated in pure form. 

Silver chloride may be isolated from a mixture of silver halides by warming with a mixture of 4 parts saturated ammonium carbonate solution and 1 part ammonia. The silver chloride is completely soluble in this mixture, and can be reprecipitated from the filtrate by acidifying with nitric acid. Only traces of silver bromide dissolve in the NH3—(NH4)2COa mixture silver iodide is insoluble. 

Isolation of Silver Halide from Model Studies... 

Isolation of Silver Halide after Reaction of Haloqen-ated Polymers... 

A similar transformation results when trimethylsilyloxy-substituted allylic halides react with silver perchlorate in nitromethane. The resulting allylic cation gives cycloaddition reactions with dienes such as cyclopentadiene. The isolated products result from desilyla-tion of the initial adducts ... 

Frimer, A. A., J. Org. Chem., 1977, 42, 3194-3196, footnote 7 A new method of preparation involves interaction of ally lie halides in solvents with 98% hydrogen peroxide in presence of silver ion and base at ambient temperature under argon. The reactions must be run in the dark to prevent precipitation of metallic silver, which will catalyse decomposition of the hydroperoxide or excess hydrogen peroxide. In an experiment not run in the dark, the hydroperoxide from 3-chlorocyclohexene ignited spontaneously after isolation and concentration. 

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