Silver difluoride

Also, in anhydrous conditions, silver reacts with fluorine and forms silver difluoride AgFj and cobalt gives cobalt(III) fluoride, C0F3, these metals showing higher oxidation states than is usual in their simple salts. 

Dimethylsulfoxide Acyl and aryl halides, boron compounds, bromomethane, nitrogen dioxide, magnesium perchlorate, periodic acid, silver difluoride, sodium hydride, sulfur trioxide... 

Silver difluoride [7783-95-1], AgF2, is a black crystalline powder. It has been classified as a hard fluorinating agent (3) which Hberates iodine from KI solutions and o2one from dilute aqueous acid solutions on heating. It spontaneously oxidizes xenon gas to Xe(II) in anhydrous hydrogen fluoride solutions (20). 

AgF2 is prepared by the action of elemental fluorine on AgF or AgCl at 200°C. Both processes result in quantitative yields. Silver difluoride should be stored in Teflon, passivated metal containers, or in sealed quartz tubes. 

Properties. Silver difluoride melts at 690°C, bods at 700°C, and has a specific gravity of 4.57. It decomposes in contact with water. Silver difluoride may react violently with organic compounds, quite often after an initial induction period. Provisions must be made to dissipate the heat of the reaction. Small-scale experiments must be mn prior to attempting large-scale reactions. 

Silver difluoride, commercially available from the same sources as those of AgF, had a 1993 price between 1000— 1400/kg. In spite of the technical success in laboratory experiments, silver fluorides have found limited use on a large scale mainly because of the high cost of the reagents. Demand for silver difluoride is less than 100 kg/yr. 

Tetrafluoropyrimidine has been prepared by direct fluoriaation of 2,4,6-trifluoropyriniidine with silver difluoride ia perfluorobutylamiae solveat (461,462). A more direct route (85% yield) is the reactioa of tetrachloropyriaiidiae and potassium fluoride ia an autoclave at 480°C for 42 h (463). 

Silver difluoride [7783-95-1J M 145.9, m 690 , d 4.7. Highly TOXIC because it liberates HF and F2. Very hygroscopic and reacts violently with H2O. It is a powerful oxidising agent and liberates O3 from dilute acids, and I2 from I soln. Store in quartz or iron ampoules. White when pure, otherwise it is brown-tinged. Thermally stable up to 700°. [Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Vol I 241 1963.]... 

Some high-valency fluorides applied at moderate temperatures are capable of replacing individual hydrogens in aromatic rings Thus benzene affords fluoro benzene on treatment with silver difluoride [/] and with chlorine pentafluoride [2] (equations 1 and 2)... 

Up to 20 products with different numbers of fluorine atoms and double bonds have been isolated from the fluonnation of benzene with silver difluoride [d], manganese trifluoride [7], potassium tetrafluoroargentate [d], and potassium hexafluoronickelate [24] The composition of the products depends on the fluorinating agents and on the temperature (Table 1)... 

Table 1. Comparison of Fluorination of Benzene with Manganese Trifluoride [7], Potassium Hexafluoronickelate [24], Silver Difluoride [6], and Potassium Tetrafluorocobaltate [6]...

On the other hand, oxidizing fluonnating agents like silver difluoride, xenon difluoride, or bromine trifluoride replace one chlorine group and then cleave the sulfur-nitrogen bond [56],... 

Tulis, A. J. et al., Proc. 7th Symp. Explos. Pyrotechnics, 1971, 3(4), 1-12 Mixtures of boron and silver difluoride function as detonators when contacted with water. 

Lead(II) oxide Non-metals Lead(IV) oxide Non-metals Nitric acid Non-metals Nitrogen oxide Non-metals Nitrosyl fluoride Metals, etc. Nitryl fluoride Non-metals Oxygen difluoride Non-metals Potassium nitrite Boron Potassium nitrate Non-metals Silver difluoride Boron, etc. Sodium peroxide Non-metals... 

Levee, J. et al., J. lnorg. Nucl. Chem., 1974, 36, 997-1001 Interaction may be explosive in the presence of finely divided nickel fluoride or silver difluoride, or nickel(III) oxide or silverQ oxide, or if initiated by local heating. The mechanism is discussed. 

Unmoderated reaction with the sulfoxide is violent, and in the presence of diluents the reaction may be delayed and become explosively violent. Although small-scale reactions were uneventful, reactions involving about 0.15 g mol of the pentafluoride and sulfoxide in presence of trichlorotrifluoromethane or tetrahydrothiophene-1,1-dioxide as diluents caused delayed and violent explosions. Silver difluoride and other fluorinating agents also react violently with the sulfoxide. 

A 1-1., four-necked, round-bottomed flask equipped with reflux condenser, sealed stirrer, thermometer, and solid addition funnel and protected from atmospheric moisture with a Drierite guard tube is carefully dried and flushed with a dry inert gas (Note I). The flask is charged with 453 g. (3.1 moles) of silver difluoride (Note 2) and 500 ml. of l,l,2-trichloro-l,2,2-trifluoroethane (Note 3), and phenyl disulfide (100 g., 0.458 mole) (Note 4) is weighed into the solid addition funnel. The stirrer is started, and phenyl disulfide is added to the slurry in small portions. An exothermic reaction occurs, and after the addition of several portions the reaction mixture reaches a temperature of 40° (Note 5). By intermittent use of a cooling bath and by adjusting the rate of addition of the disulfide, the reaction temperature may be maintained between 35° and 40°. The addition of the phenyl disulfide requires 45-60 minutes. On completion of the addition the suspension of black silver difluoride has been converted to yellow silver monofluoride, and the exothermic reaction gradually subsides. The reaction mixture is stirred for an additional 15-30 minutes without external cooling and then quickly heated to reflux. 

Sebacic acid, 43, 39 Sebacoyl chloride, 43, 37 2,2 -SebacoyldicycIohexanone, 43, 34 Silver difluoride, reaction with phenyl disulfide, 44, 82 Silver monofluoride, 44, 82 Sodium amide, as catalyst for carbona-tion of methylacetylene, 42, 98 for formation of sodium sodiophenyl-acetate, 40, 38... 

A technical grade of silver difluoride (approximately 85%) is available from Harshaw Chemical Company. Better grades of silver difluoride are available and may be employed. It is important that the silver difluoride be a black powder. If the material is light brown and lumpy, a lower yield of product may be obtained. Normally, the contents of a 1-lb. can (approximately 435-470 g.) are employed. 

Silver difluoride, 0014 Silver fluoride, 0013 Sodium chloride, 4036 Sodium iodide, 4623 Tantalum pentachloride, 4185 Tellurium tetrabromide, 0296 Thallium, 4922 Tin(II) chloride, 4116 Tin(IV) chloride, 4174 Tin(II) fluoride, 4331 Titanium(II) chloride, 4117 Titanium dibromide, 0284 Titanium diiodide, 4630 Titanium tetrachloride, 4176 Titanium tetraiodide, 4638 Titanium trichloride, 4158... 

Trifluoromethyl hypofluorite was first made by Cady by passing methanol [184] or carbon monoxide [185, 186] with fluorine over silver difluoride at elevated temperatures. Later, trifluoromethyl hypofluorite and higher perfluoroalkyl hypofluorites were prepared by treating the appropriate carbonyl compound with fluorine in the presence of dry caesium fluoride at sub-zero temperatures (Fig. 81) [187-189]. 

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