Silver hexafluoroarsenate

The use and handling of arsenic fluorides and liquid SOj have been described. Powdered silver metal (5.4 g, 50 mmol) is filled into part A of the flask, and about 25 mL of SO2 is condensed as described above. Similarly, arsenic pen-tafluoride (13.6 g, 80 mmol, 5.4 mL) is condensed from the storage tank into a small metered trap at -78° = 2.47 g/mL) and then retransferred into 

Silver hexafluoroarsenate is a white crystalline solid, sensitive to moisture and light. Therefore, it should be stored in a dark sealed tube. It is very soluble in SO2, insoluble in nonpolar solvents such as dichloromethane, and soluble in complexing solvents such as acetonitrile and dioxane with complex formation. Contact with such solvents should be avoided, since the solvent complexes are very stable and the salt is no longer useful for complexation. 

Commercially available sublimed sulfur is dried under vacuum. Because the product is sensitive to daylight, the reaction is carried out with the flask wrapped 

Bis(cydo-octasulfur)silver( 1 +) hexafluoroarsenate(l —) is a moisture-sensitive pale yellow crystalline solid that decomposes in the daylight to yield black AgjS. It can be stored indefinitely in a dark sealed tube under nitrogen. The compound is soluble only in SO2, insoluble in nondonor solvents, and decomposes in donor solvents, yielding the solvent complex and elemental sulfur. 

An IR spectrum (Nujol mull) with absorption bands at 712 (s), 696 (s), 676 (s), and 395 (s) cm , and a Raman spectrum with bands at 675 (w), 470 (m), 465 (m), 437 (w), 263 (w), 223 (s), 162 (m), and 155 (s) cm have been recorded. The structure has been established by X-ray diffraction. The unit cell consists of four ion pairs in the space group C2/c. The silver atom is distorted 4-coordinate with 1,3 linkage of the two sulfur rings, which exhibit only a slight change in their geometry compared to free cyc/o-octasulfur. 

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Although 1,3,5-triselenane (120 R = H) is unstable, the heterocycle and its oligomers form relatively stable complexes with silver salts. With silver hexafluoroarsenate in sulfur dioxide, for example, 1,3,5-triselenane affords a complex [[(CH2Se)3]2Ag]AsF6 in which the silver atom is equidistant from all the selenium atoms in both heterocyclic subunits <83JOM(249)97>. 

SILVER HEXAFLUOROARSENATE AND BIS(cjtc/o-OCTASULFUR)SILVER(l + ) HEXAFLUOROARSENATEd - )... 

Although charge transfer complexes with Sg, metal complexes with ionic sulfur moieties/ and several covalent compounds containing homocyclic sulfur rings are well established, the reaction of cyc/o-octasulfur with silver hexafluoroarsenate in liquid sulfur dioxide provides a new synthetic pathway to a coordination compound of a neutral Sg ring/ Earlier work has shown that metal hexafluo-roarsenates form complexes with very weak O, N, and S donors, using liquid sulfur dioxide as solvent/... 

Arsenates are oxidizing agents and are reduced by concentrated hydrochloric acid or sulfur dioxide. Treatment of a solution of orthoarsenate with silver nitrate in neutral solution results in the formation of a chocolate-brown precipitate of silver orthoarsenate, Ag AsO, which may be used as a test to distinguish arsenates from phosphates. With hydrofluoric acid, orthoarsenate solutions yield hexafluoroarsenates, eg, potassium hexafluoroarsenate [17029-22-0] (KAsFg)2 H2O. Arsenates of calcium or lead are used as insecticides sodium arsenate is used in printing inks and as a mordant. 

SiaAgAsFt, Silver(l+), bis([Pg.295]

As the cofacial dimer 1 is a readily available compound, the best method for the preparation of thiatriazinium salts is to treat 1 with nitrosyl tetrafluoroborate or hexafluorophosphate. The reaction mixture must be kept under inert gas during the evolution of nitrogen oxide. A direct method is the reaction of 1-fluorothiatriazines, e.g. 3, with arsenic(V) fluoride or phosphorus pentafluoride. The so-called silver salt method consists of the reaction of 1-chlorothia-triazincs with silver(I) hexafluoroarsenate in liquid sulfur dioxide. 

Silver vanadium oxide is combined with a conductive carbon and a binder like PTFE to make the cathode. The usual electrolyte solution used is lithium hexafluoroarsenate (LiAsFs) in mixed organic solvents, like propylene carbonate and 1,2-dimethoxyethane. 

Polyselenophene (Fig. 16c) has been prepared. However, due to the difficulty in obtaining the monomer, the polymer has not been extensively investigated. Polymers of selenophene prepared electrochemically under appropriate conditions yield films with maximum conductivities of 10"- S cm [330,331]. Samples of p-doped selenophene produced chemically have conductivities on the same order of magnitude [332]. Applying 3-10 V between two electrodes in an electrolyte of 0.1 to 1 M lithium tetrafluoroborate or lithium perchlorate dissolved in benzonitrile or propylene carbonate gives polyselenophene films, as does the combination of tetrabutylammonium tetrafluoroborate in benzonitrile. However, other salts such as lithium hexafluoroarsenate, lithium hexafluorophosphate, tetrabutylammonium perchlorate, or silver perchlorate in combination with solvents such as acetonitrile or nitrobenzene were reported to produce either powders or no products at all [330,331,333]. 

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