Aurous acetylide

Burkard later tried to clarify the issue of the product composition and based on the results of elemental analysis concluded that the substance is mercurous acetylide monohydrate—Hg2C2-H20 [65]. Another not very well described way for preparing mercurous acetylide is the reaction of cuprous acetylide in aqueous suspension with mercurous nitrate [48]. Both preparation methods must be also carried out in the absence of daylight. 

Aurous acetylide is a yellow compound, it decomposes by boiling in water into its constituents (acetylene does not form), and it also decomposes by the action of hydrochloric acid (acetylene and black aurous chloride form). Cold ferric chloride or cupric sulfate does not decompose it. When the acetylide is heated very gradually, it decomposes without explosion [67]. 

Aurous acetylide can be prepared by the reaction of acetylene with sodium aurous thiosulfate Na3Au(S203)2 in a strongly alkaline solution. The product forms as a yellow flocculent precipitate. Sodium aurous thiosulfate is prepared by reaction of auric chloride with sodium thiosulfate [67]. 

Aurous acetylide does not form when passing acetylene through an aqueous solution of auric chloride. Instead metallic gold precipitates. Precipitation does not occur when introducing acetylene into a solution of auric chloride alkalized by potassium hydroxide nor into aqueous or ammoniacal solutions of potassium auric cyanide [67]. Unwanted formation of aurous acetylide has been reported during preparation of some alkynylgold(I) complexes [68]. 

Nieuwland, J.A., Vogt, R.R. The Chemistry of Acetylene. Retnhold Publishing Corporation, New York (1945) 

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When thoroughly dried, aurous acetylide readily expl, not only on rapid heating(see above) but also on impact, friction or even when touched with a camel s hair brush. Several explns have occurred during its prepn in various labs. When expld,it produces a flame and leaves a black, pondered residue of gold. Reppe et al (Ref 3) found Aua Ca as a suitable catalyst in prepn of some org compds... 

Aurous Acetylide. See Gold Acetylides under Acetylides... 

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