Silver “subfluoride

Pure silver subfluoride [1302-01 -8] 2 greenish shiny crystalline material, or yellowish green soHd if contaminated with AgF. It decomposes in water... 

Silver Fluoride. Silver fluoride, AgF, is prepared by treating a basic silver salt such as silver oxide or silver carbonate, with hydrogen fluoride. Silver fluoride can exist as the anhydrous salt, a dihydrate [72214-21-2] (<42° C), and a tetrahydrate [22424-42-6] (<18° C). The anhydrous salt is colorless, but the dihydrate and tetrahydrate are yellow. Ultraviolet light or electrolysis decomposes silver fluoride to silver subfluoride [1302-01 -8] Ag2p, and fluorine. 

Silber-fluoriir, n. silver subfluoride, -fohe, /. silver foil. 

It is convenient here to consider the compound disilver monofluoride (or silver subfluoride). This was reported to have an anti-cadmium iodide structure in early work (5), and this has been confirmed more recently (6). From X-ray single-crystal results the unit cell is hexagonal, a = 2.996, c = 5.691 A, space-group C3m, and the Ag—F separation 2.451 A, almost identical with that in silver monofluoride (2.468 A). The structure consists of layers, with a plane of fluorine atoms sandwiched between two planes of silver atoms, giving the fluorine atom a coordination of six silver atoms, the same as in silver monofluoride. The silver atoms have separations of 2.996 and 2.814 A, compared with 2.889 A in the metal itself, and in line with the metallic conductivity of the compound. 

Silver(II) oxide, 4 12 Silver oxynitrate, Ag70sN03, formation of, by silver(II) oxide, 4 13 Silver subfluoride, Ag2F, 6 18,19 Sodium, calcium metal preparation from a solution in, 6 18, 24... 

Silver subfluoride, Ag2F.—When a saturated solutidn of silver fluoride is heated with finely divided silver, a golden-yellow, crystalline precipitate of the composition Ag2F is produced.11 The reaction is attended by the evolution of 0-7 Cfal.,12 and the heat of formation of the subfluoride from its elements is 26-3 Cal. At 180° C. water-vapour converts the fluoride into the suboxide, Ag40.13... 

Silver subchloride, AgaCl.—When silver subfluoride is heated with phosphorus trichloride at 140° C., silver subchloride is formed.8 It is also a product of the interaction of silver nitrate and cuprous chloride, of a colloidal solution of silver and chlorine-water,9 and of silver-foil and weak oxidizers such as cupric chloride. 

Silver suboxide, Ag40.—Several experimenters have described the formation of a suboxide by reduction of silver compounds, but the subject seems to merit further investigation. Silver subfluoride is said to react with water-vapour at 180° C., yielding a black powder of the... 

Silver subsulphide, Ag4S.—Hydrogen sulphide precipitates from silver subfluoride a black, amorphous substance, possibly Ag4S,.but probably only a mixture of silver and its sulphide.6... 

Disilver fluoride (silver subfluoride ) has been prepared by the cathodic reduction of aqueous silver(I) fluoride solutions at low current densities1 and by the reaction of elemental silver with silver(I) fluoride at tem-... 

Silver subfluoride is stored in opaque glass bottles. Used to fluorinate organic compounds. 

An example of a compound of this type is silver subfluoride, Ag2p, made by leaving metallic silver in contact with the normal fluoride, AgF, in the dark. It forms small crystals with a bronze reflex, and is a good conductor of electricity. 

Antoine N. Guntz (Wiesbaden, 9 July 1859-Nancy, 7 August 1936), professor of general chemistry in the University of Nancy (1884), did much research in inorganic chemistry, including the preparation of pure alkaline-earth metals, nitrides, etc. He discovered silver subfluoride, AggF, and prepared metallic radium (1910) and many anhydrous nitrates. 

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