Silver acetylide, decomposition

Silver acetylide decomposition was studied [679] by X-ray diffraction and microscopic measurements and, although the a—time relationship was not established, comparisons of intensities of diffraction lines enabled the value of E to be estimated (170 kj mole 1). The rate-limiting step is believed to involve electron transfer and explosive properties of this compound are attributed to accumulation of solid products which catalyze the decomposition (rather than to thermal deflagration). 

Kabanov, A. A. etal., Russ. Chem. Rev., 1975, 44, 538-551 Application of electric fields to various explosive heavy metal derivatives (silver oxalate, barium, copper, lead, silver or thallium azides, or silver acetylide) accelerates the rate of thermal decomposition. Possible mechanisms are discussed. 

Muraour, Effect of Electron Impact Upon Lead Azide and Silver Acetylide-Theoretical Observations Upon the Thermal Decomposition of Explosives , Chim Ind 30, 39- 40 (1933)... 

McCowan [38] used electron microscopic and X-ray measurements to study the thermal decomposition of silver acetylide. Although detailed or-time relationships could not be established, the value of was estimated to be 170 kJ mol in the interval 388 to 408 K. The rate-limiting step was identified as the production of an electron and an acetylide radical that react fiirther to yield amorphous carbon. Decomposition is catalyzed by the product, probably metallic silver, and explosion was ascribed to the accumulation of catalyst rather than heat. 

The electron bombardment of explosives has been undertaken by various investigators in an effort to initiate or decompose the material under study. One of the early investigations was undertaken by Kallmann and Schrankler [30], who bombarded TNT, mercury fulminate, nitrocellulose, and to some extent, picrates and azides with 10-kV, 1-mA electrons in vacuo but were unable to produce explosions. However, when heavy ions of argon and mercury were used, initiations were achieved with several substances with each of the ions. Muraour [31 ] subjected lead azide and silver acetylide to 90 kV at 3 mA for 3 min and only achieved explosion with silver acetylide. Both explosives blackened upon electron irradiation. Muraour believed that the explosion was either a thermal effect or that, by chance, a sufficiently large number of molecules decomposed at one point to bring about complete decomposition. 

ARGENTUM, METALLIC (7440-22-4) Ag In powder form, contact with acetylene may form the shock-sensitive explosive silver acetylide. Contact with ammonia or ammonium compounds may form compounds that are explosive when dry. Violent decomposition may be caused by contact with fuhninic acid strong hydrogen peroxide solutions oxalic acid tartaric acid oxygen gas will be liberated. This entry may also apply to other silver salts and compounds. Evaluate before use. Many... 

Reactivity and Incompatibility Contact of metallic silver and silver compounds with acetylene may cause formation of silver acetylide, which is a shock-sensitive explosive. Contact with ammonia may cause formation of compounds that are explosive when dry. Contact with strong hydrogen peroxide solutions causes violent decomposition with the formation of... 

Purpose To demonstrate the formation and decomposition of the silver acetylide of a terminal alkyne. 

Formation and Decomposition Add 3 mL of the diluted silver amrronia complex solution to about 0.1 mL of 2-methyl-3-butyn-2-ol in a test tube, and note the formation of the silver acetylide salt. Collect the silver salt by vacuum filtration of the aqueous solution be careful not to let the silver salt dry, because the dry salt Is explosive. Transfer the wef silver salt to a clean test tube, and add a small amount of dilute hydrochloric acid. Observe what changes occur, especially in the color and form of the precipitate. 

Simple silver acetylide was first prepared by Quet in 1858 even before acetylene itself had been identified. The procedure was based on the introduction of a gas obtained from decomposition of alcohol by electric discharge into an ammoniacal solution of silver chloride [5, 7, 8]. 

Explosibility. Liquid ethylene oxide is stable to detonating agents, but the vapor will undergo explosive decomposition. Pure ethylene oxide vapor will decompose partially however, a slight dilution with air or a small increase in initial pressure provides an ideal condition for complete decomposition. Copper or other acetylide-forming metals such as silver, magpesium, and alloys of such metals should not be used to handle or store ethylene oxide because of the danger of the possible presence of acetylene. Acetylides detonate readily and will initiate explosive decomposition of ethylene oxide vapor. In the presence of certain catalysts, liquid ethylene oxide forms a poly-condensate. 

See other IRRADIATION DECOMPOSITION INCIDENTS, SILVER COMPOUNDS See related METAL ACETYLIDES... 

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