Silver acetylide

Silver acetylide is an inorganic chemical compound with the formula Ag₂C₂, a metal acetylide. The name derived from the way it is synthesized, the alternative silver carbide is not used in literature, although the substance is similar to calcium carbide . It is a heat and shock sensitive high explosive with the unusual property that on ignition it does not evolve any gas:

:Ag₂C_2(s) → 2 Ag_(s) + 2 C_(s)

Synthesis

Silver acetylide can be produced by passing acetylene gas through a solution of silver nitrate. [cite journal|author = G.-C. Guo, Q.-G. Wang, G.-D. Zhou, T. C. W. Mak|title =Synthesis and characterization of Ag₂C₂·2AgClO₄·2H₂O: a novel layer-type structure with the acetylide dianion functioning in a ₆-η¹,η¹:η²,η²:η²,η² bonding mode inside an octahedral silver cage|journal= Chem. Commun.|year= 1998|pages= 339–340|doi=10.1039/a708439k]

The equation is as follows:

:2 AgNO_3(aq) + C₂H_2(g) → Ag₂C_2(s) + 2 HNO_3(aq)

The reaction product is a greyish to white precipitate. This is the same synthesis from Berthelot in which he first found silver acetylide in 1866. [cite journal
author = M. P. Berthelot
title =Ueber eine neue Klasse zusammengesetzter metallhaltiger Radicale (A new class of combined metalic radicals)
journal= Annalen der Chemie
year= 1866
pages= 245–253
volume = 138
issue = 2
doi = 10.1002/jlac.18661380215]

Silver acetylide can be formed on the surface of silver or high-silver alloys, eg. in pipes used for transport of acetylene, if silver brazing was used in their joints.

Toxicity

As with all silver salts, silver acetylide is toxic. Ingesting as little as 2 grams can be fatal.Fact|date=February 2007

References