Silver© mercaptide compounds

Many silver(I) mercaptide compounds, Ag(S/ ) , are known, and Akerstrom [38] reported a systematic study of primary, secondary, and tertiary silver(I) mercaptides highlighting the relationship between substituent R, polymeric nature, and the solubility of the silver(I) mercaptides. As observed for the analogous gold compounds, the solubility of many silver(I) mercaptide compounds is very limited. However, some sterically hindered compounds, such as silver tert-alkylmercaptides have been shown to be soluble enough to be used within liquid gold formulations in combination with the equivalent gold compounds [52]. 

Fitch expanded on his work on gold(I) mercaptides in combination with silver(I) mercaptides to include the synthesis of novel gold-silver mercaptide precursor compounds [53], These were prepared by simply reacting the gold(I) mercaptide compounds with an eqnimolar amonnt of silver(I) mercaptide or silver(I) carboxylate at elevated temperatures in a suitable solvent (for example, toluene) (Equation 15.5). 

A number of compounds of the types RBiY2 or R2BiY, where Y is an anionic group other than halogen, have been prepared by the reaction of a dihalo- or halobismuthine with a lithium, sodium, potassium, ammonium, silver, or lead alkoxide (120,121), amide (122,123), a2ide (124,125), carboxylate (121,126), cyanide (125,127), dithiocarbamate (128,129), mercaptide (130,131), nitrate (108), phenoxide (120), selenocyanate (125), silanolate (132), thiocyanate (125,127), or xanthate (133). Dialkyl- and diaryUialobismuthines can also be readily converted to secondary bismuthides by treatment with an alkali metal (50,105,134) ... 

In this part of the chapter we discuss (a) the controlled thermolysis of thiolate solutions in polystyrene matrix at temperatures above the polymer glass transition temperature and (b) the reaction mechanism in the case of silver-polystyrene nanocomposite systems. However, the same reaction mechanism is probably involved in the thermolysis of other mercaptide-polystyrene systems. This technique has proven to be an excellent new preparative scheme for the generation of both metal and sulfide clusters in polymers. In particular, high-molecular-weight n-alkanethiolates have shown to be the most effective compound class since the low volatility of thermolysis by-products avoids film foaming during the annealing process. 

In the original formulation [81a], DBN and a slight molar excess of AgN03 in MeCN solution were used. Depletion of the starting penicillanic ester was followed by tic and, when complete, obtained silver azetidinyl mercaptides 126 were in situ treated with acyl chlorides to afford thioesters 127 these in turn were oxidized at the butenoate double bond to give lH-4-thioesters 128, key intermediates of Woodward s original phosphorane-thioester cyclization route to penems [1, 48], or ozonized to the iV-oxalo compounds 129, immediate penem precursors by a newly discovered reductive dicarbonyl coupling [82]. 

Most mercaptides are not available as commercial products, since large-scale applications of these chemical compounds are quite limited (only mercaptides of tin and antimony are used industrially as thermal stabilizers for poly(vinyl chloride) [de Sousa et al., 2000 Qu L. et al., 2002]). However, these compounds can be synthesized in a very simple way. Owing to their low water solubility, mercaptides can precipitate by reacting thiols (or thiophenols) with aqueous solutions of the corresponding metal salts. In addition to the well-known mercaptides of mercury, lead, zinc, and copper, many others, such as mercaptides of silver, gold, platinum, palladium, iridium, nickel, iron, cobalt, antimony, bismuth, and cadmium, have been prepared. 

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