Silver® thiolates

The family of primary silver thiolate compounds AgSC H2n+1 ( = 4, 6, 8, 10, 12, 16, or 18), which in the solid state consists of 2x,[AgSR] layers, behaves as thermotropic liquid crystals. On heating, they display successively lamellar (smectic A), cubic, and micellar mesophases.969... 

Silver(I) trifluoromethanethiolate (AgSCF3) has been used to prepare trifluoromethyl aryl sulfides by reaction with iodide.996 A mixed silver-zinc thiolate complex [Ag4Zn2(SC6H2-Pr -2,4,6)6(OTf)2] has been prepared by reaction of AgOTf with Zn[N(TMS)2]2 in the presence of the thiol.99 Solid-state 109Ag NMR can be a sensitive environment probe for silver thiolates,998 overall for biological thiolates ligands as cysteine,999 or proteins such as metallothionein.1000,1001... 

The pristine environment of the gas phase can give some surprising reactions, viewed from the perspective of condensed-phase chemistry (2). Silver nitrate dissolved in acetonitrile added to a solution of benzenethiol in acetonitrile gives an immediate white precipitate and a brown gas is given off. The insoluble polymeric layered silver thiolate (3) is formed as the solvent abstracts a proton forming nitric acid the acid attacks the solvent. 

Until recently, little structural information has been available for silver thiolates. Based on molecular weight measurements it was suggested that for [AgSR] when R was a tertiary alkyl then n = 8, while when R was a secondary alkyl then n = 12. For primary alkanethiolates which were generally insoluble, unreliable high molecular weights were obtained, indicative of non-molecular structures. 

The crystal structures of several silver thiolates have now been reported and, in general, the Ag—S distances were between 240 and 280 pm.299-302 If longer distances (e.g. 330 pm) or secondary bonding were included in the interpretation, then molecular cycles and a variety of molecular cages could be recognized. These included [Ag4(SR)6]2-, [Ag5(SR)6], ... 

The sensitivity of silver NMR chemical shifts is illustrated by a series of studies of silver thiolates and related compounds.65 67 In [(C6H5)4P]2[Ag4(SCH2C6H4CH2S)3]... 

The chemical shifts of Ag-S compounds have been recorded in studies of a series of silver thiolates and related compounds (Fijolek et al. 1996) which indicate that the... 

The penem-3-thione (97 J) may be synthesized from the silver thiolate by the use of thiocarbonyldi-imidazole (TDI). 

Silver thiolate compounds (AgSR) adopt a bilayer structure in the crystalline state [168] with a central slab of 3-SR and trigonal planar Ag. On melting, these compounds form lamellar, cubic, micellar and hexagonal columnar mesophases, depending on the length of R [169]. 

Cubic phases have also been observed in silver thiolates (AgSC H2 +i)... 

Figure 4 Comparison of copper and silver thiolate complexes of the same thiolate ligand and with the same formula unit. Perspective view of (a) [Cu(SC6H4-o-SiMe3)]i2 and (b) [ Ag(SC5H4-o-SiMe3) 4]2, highlighting the CU12S12 core and the fusing of two Ag4S4 units via Ag S secondary interactions (3.05...

The other way to generate thioesters at the penultimate step of penem synthesis is acylation of silver thiolates 226. These compounds are conveniently obtained by cleavage of the corresponding trityl sulfides 225 with silver nitrate and methanol [51a, 144] trityl methyl ether and nitric acid (trapped by pyridine or, better, imidazole) are liberated in the process. Tetrahydropyranylthioethers 227 [145] and acetyl thioesters 228 [51a, 52] were also reported to be cleavable to the corresponding argentiothio-phosphoranes of general formula 226. 

Condensation of 102c with symmetric or mixed (allyl, trimethylsilylethyl) ketomalonic esters gave the carbinolamides 283, which were reduced to 285 by chlorination (SOCl2/pyridine) and treatment with zinc (i-PrOH, AcOH in CH2CI2 concomitant TCE removal). The silver thiolates 286, obtained by tritylthio cleavage under the usual conditions, reacted with thiocarbonyldiimi-dazole to produce the cyclic compounds 288 directly. Mono-deprotection with... 

Another possible means of obtaining multinuclear sulfur-bridged silver clusters would be to react silver thiolates (AgSR) with carbon disulfide (Scheme 3.11). 

The largest clusters synthesized to date have been obtained by the reaction of silver thiolates with S (SiMe3)2 in the presence of bidentate phosphanes. Depending on the reactants, solvents and molar ratios used, clusters contaming several hundreds of silver atoms can be synthesized (Scheme 3.12). The formation of these metal-rich compounds can only be observed in the presence ofbidentate phosphanes. Although... 

Scheme 3.12 Synthesis of various metal-rich, sulfur-bridged silver clusters by reactions of silver thiolates S(SiMe3)2 In the presence of bidentate phosphanes.

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