Mercuric fulminate preparation

When I came to Marburg, I found in the collection of preparations a glass-stoppered botde containing an ounce or more of mercuric fulminate. I took the flask and carried it to a nearby deep stone-quarry, and threw it in. 

Silver Azide, Cadmium Azide, Cupric Azide, Triazidotrinitrobenzene, Chloratotrimercuraldehyde, Nitrogen Suifide Hexamethylenetriperoxidediamine Until WWI, Mercuric Fulminate was the principle initiating agent used, but Lead Azide has now replaced it. Lead azide is not the most powerful azide, but is more stable and less dangerous to handle than some of the other ones. Cadmium Azide, for example, is more powerful than Lead Azide but is unsuitable as an initiating agent because it is difficult to prepare and is soluble in water... 

In an interesting sequence of reactions, Grundmann and co-workers have prepared 5-amino-4-nitroisoxazole (67) from the sodium salt of nitromalonaldehyde and hydroxylamine.59 The initially formed sodium malon-dialdoxime nitronate 65 is diacetylated and cyclized to the furazan oxide 66 acid hydrolysis, followed by rearrangement in alkali gives the 5-amino-4-nitroisoxazole (Scheme 13). The same product has also been detected in the decomposition of mercuric fulminate. 

Mercuric fulminate is prepared by the action of nitric acid on mercury and the subsequent action of ethyl alcohol. The fulminate settles out as a white powder which is very explosive when dry but may be safely... 

Fulminic Acid, C=N--OH.—Salts of this acid are obtained when nitric acid, alcohol, and mercury or silver are brought together in certain proportions. Mercuric fulminate, (CNO)2Hg, is prepared for use in percussion caps, which are used to explode gunpowder, dynamite, and other explosives. Free fulminic acid is a very unstable volatile liquid. It resembles closely hydrocyanic acid in odor and poisonous properties. 

Other metallic fulminates cannot be synthesized directly by reaction of metal with nitric acid and sequentially with ethanol in the same way as mercury or silver fulminates (and probably also complex Na[Au(CNO)2]). They are therefore mostly prepared by reaction of mercuric fulminate with the relevant amalgam. 

Fulminate can, however, be prepared from a compound which contains only one carbon atom. The sodium salt of nitromethane gives with an aqueous solution of mercuric chloride at 0° a white... 

Amalgams with the alkali metals are readily formed by plunging the latter into warmed mercury. They are of interest in that by using a mercury cathode, Sir Humphry Davy in 1807 was able to isolate both potassium and sodium by electrolysis of potash and soda (p. 144). Mercury is used to-day in the commercial manufacture of caustic soda and hydrochloric acid by the electrolysis of brine. It is used also as the raw material for the preparation of mercuric oxide, vermilion, mercurous and mercuric chloride, fulminate and other derivatives. The oxide is of special historical interest as it led 170 years ago to the discovery of oxygen (p. 21)... 

He showed that sodium salts of aliphatic primary and secondary nitrocompounds react with acids to form carbonyl compounds 2R2CHNO2 = 2R2C0+N2O+ H2O. Nef supported the theory of bivalent carbon. In the preparation of the explosive mercuric salt of nitromethane, he found that mercury fulminate is formed and regarded fulminic acid as C N OH, the reaction being Hg(CH2 N0 0)2==Hg(0-N C)2 + 2H20. He prepared the explosive addition compound of fulminic acid and hydrogen chloride, HON CHCl. In researches on acetylene compounds he prepared explosive di-iodoacetylene, IC-CI (he formulated it IgC.-C). He discovered the reaction between sodium acetylene and a ketone, followed by hydrolysis, to form an acetylenic carbinol ... 

Berthollet recognised in 1788 that in several cases if metals when oxygenated function in the manner of alkalis with acids, they will behave as acids towards alkalis . He obtained solid calcium plumbite by boiling litharge with lime water, discovered fulminating silver from silver oxide and ammonia, obtained triple salts of mercury, and found that mercury oxide combined with lime, and he says that Lavoisier had obtained crystals from a solution of mercuric oxide in ammonia. Berthollet prepared pure caustic potash by solution in alcohol and evaporation. ... 

The mercury fulminate (MF) formula is HgCC N" —0 )2 with a covalent bond between the mercury and carbon atoms [20]. Its crystal density is reported to be 4.42-4.43 g cm [29, 30, 39, 40], but recent results of X-ray analysis updated it to 4,467 g cm [21]. Bulk density depends on crystal size and shape—it is reported to be between 1.35 and 1.55 g cm [38]. The heat of formation of MF is reported as being between —268 and —273 kJ moP [29, 41, 42]. The structure of the MF molecule and its crystal was published recently by Beck et al. [21]. Pure and ordinarily prepared mercury fulminate is, for all practical purposes, not hygroscopic, but its hygroscopicity rapidly increases in presence of impurities (e.g., mercury oxalate, calomel, mercuric chloride), which are generally present in the industrial... 

An alternative method of laboratory preparation of mercury fulminate is based on decomposition of the mercury salt of nitromethane published by Nef [14]. The mercuric salt is prepared in the first step of a reaction when mercuric chloride reacts with the sodium salt of nitromethane. The mercuric salt of nitromethane decomposes in a second step by boiling with dilute hydrochloric acid to produce MF [14] ... 

Fulminates other than those of Hg and Ag (and also complex Na[Au(CNO)2] from AuCls [110]) cannot be prepared directly by reaction of the metal with nitric acid and subsequently with ethanol like MF or SF [15, 33]. Several reasons exist that make direct formation of other fulminates impossible. Wohler and Martin reported that solubility of most fulminates in the reaction mixture is a reason why only MF and SF can form directly. Most other fulminates are soluble and unstable in the reaction mixture, in which they decompose [57]. Another reason is that the fulminic acid too readily forms complex salts and therefore simple fulminates cannot be isolated [35]. A catalytic effect of noble metals (Hg, Ag) on some of the reaction steps of fulminate formation was reported by Krauz. He mentioned the analogy of the catalytic effect of mercuric ions on hydrocarbons that are oxidized to the relevant nitrophenols in dilute nitric acid [35]. 

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