Sulfur silver complex

The preparation of a series of transition metal complexes (Co. Ni. Pd. Pt, Ir. Au. Cu. Ag) with ambident anion (70) and phosphines as ligands has been reported recently (885). According to the infrared and NMR spectra the thiazoline-2-thione anion is bounded through the exocyclic sulfur atom to the metal. The copper and silver complexes have been found to be dimeric. 

Silver and sulfur combine even in the cold to form silver sulfide. The tendency of silver to tarnish is an example of the ease with which silver and sulfur compounds react. PoHshes that contain silver complexing agents, such as chloride ion or thiourea, are used to remove silver tarnish. 

Sulfur Complexes. Silver compounds other than sulfide dissolve in excess thiosulfate. Stable silver complexes are also formed with thiourea. Except for the cyanide complexes, these sulfur complexes of silver are the most stable. In photography, solutions of sodium or ammonium thiosulfate fixers are used to solubilize silver hahdes present in processed photographic emulsions. When insoluble silver thiosulfate is dissolved in excess thiosulfate, various silver complexes form. At low thiosulfate concentrations, the principal silver species is Ag2(S203) 2j high thiosulfate concentrations, species such as Ag2(S203) 3 are present. Silver sulfide dissolves in alkaline sulfide solutions to form complex ions such as Ag(S 2 Ag(HS) 4. These ions are... 

Several ligands containing pyridine or related groups and sulfur atoms have been synthesized and the silver complexes studied the ligands used are shown in Figure 15. Many of the complexes have a supramolecular structure. 

Since there is an enormous density of such equivalent sites on the surface of a silver halide microcrystal, it would be surprising if a single speck of Ag2S were formed on each grain even under optimum conditions of sulfur sensitization. The sensitizer forms an adsorption silver complex which reacts to form an adsorbed molecule of Ag2S. 

The discoloring is likely to be caused by the photoreduction of silver chloride and/or silver phosphate in the skin. X-ray dispersive analysis of skin and other tissues reveals that the granules consist of silver complexed with sulfur and/or selenium. The photoreduced deposits are not removed by the body, and there are no clinical means of removing them. 

Fig. 8. Molecular structure of the gold-sulfur-silver-bromine core of the cationic complex 226. Only the N- and C-donor atoms of the cycloaurated damp ligands are shown.

In addition to the phosphorus ylide complexes, arsenic and sulfur ylide complexes of silver have been obtained, although no structural reports exist. While the arsenic derivatives match the phosphorus ylide complexes for stability of the Ag products, the sulfoxonium ylide complexes are somewhat less stable. 

This section includes selected examples of electrochemistry of gold and silver complexes with other ligands and structural types that were not included in previous sections. We have also included a list of references divided into the following areas that can be consulted for additional information sulfur- and nitrogen-containing macrocycles , porphyrins " and clusters . 

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