Mercury Fulminate preparation

Mercury fulminate prepared by one of the methods outlined above is tested to check the acid content and the content of other mercury compounds. When tested with litmus paper, the moist product should give a neutral reaction. A 5 g test sample mixed with 2 g of sodium hydrogen carbonate should not give a black or bluish tint. 

The other potential isomer of HOCN (in addition to isocyanic acid [H-N=C=0] and cyanic acid [H-O-CfeN]) is fulminic acid (H-0-N sC ), which is also incapable of isolation as the free acid (since attempts to do so result in polymerization). However, salts of fulminic acid are known and mercury fulminate, prepared by treatment of a mixture of mercury and ethanol with nitric add, is used commercially as a detonator (blasting cap) for explosives. 

Mercury fulminate has the formula Hg(ONC)2. It was probably discovered by Howard in 1800 and its constitution was established by Nef. The method of preparation is known as the Chandelon process and is a complex reaction studied by Wieland. Mercury is dissolved in an excess of warm nitric acid and ethyl alcohol added to the resulting solution. Considerable bubbling occurs in the strong reaction, so this is usually carried out in capacious glass balloons . At the end of the reaction the mercury fulminate remains as a dense precipitate which is filtered and washed several times. 

Attempts to follow a published procedure for the preparation of 1,3 -dithiole-2-thione-4,5-dithiolate salts [1], involving reductive coupling of carbon disulfide with alkali metals, have led to violent explosions with potassium metal, but not with sodium [2], However, mixtures of carbon disulfide with potassium-sodium alloy, potassium, sodium, or lithium are capable of detonation by shock, though not by heating. The explosive power decreases in the order given above, and the first mixture is more shock-sensitive than mercury fulminate [3],... 

Mercury fulminate, readily formed by interaction of mercury(II) nitrate, nitric acid and ethanol, is endothermic (AH°f (s) +267.7 kJ/mol, 0.94 kJ/g) and was a very widely used detonator. It may be initiated when dry by flame, heat, impact, friction or intense radiation. Contact with sulfuric acid causes explosion [1], The effects of impurities on the preparation and decomposition of the salt have been described [2],... 

The need for great care to avoid the possibility of detonation of perchloryl compounds by exposure to shock, overheating or sparks is stressed. The compounds are generally more sensitive to impact than mercury fulminate and are of comparable sensitivity to lead azide [1], A range of highly explosive alkyl perchlorates [2] and perchlorylamines [3] have been prepared by interaction of dichlorine heptaoxide with alcohols or amines in carbon tetrachloride solution. The solutions of the products were not sensitive to mechanical shock and could... 

For the terrorist, TATP and HMTD offer easy sources of primary explosives. Consulting the do-it-yourself literature, it can be seen that there are two other commonly recommended primary explosives—lead azide Pb(N3)2 and mercury fulminate Hg(ONC)2, but these are difficult to prepare cleanly. The synthesis of diazodinitrophenol (DDNP) (Fig. 2.5), common in commercial detonators, is reported in such publications, but apparently is rarely attempted by clandestine chemists. Typically, the brisance of a primary is less than TNT, but the efficacy is the fact that a shock wave can result from a relatively mild insult. 

Mercury fulminate is prepared by the reaction of mercury metal with strong nitric acid and ethanol. The preparative method involves pouring a nitric acid solution of mercury(II) nitrate into ethanol. The reaction is not well understood. 

According to Romocki [2], in 1630, the Dutchman, van Drebbel was the first chemist to investigate mercury fulminate, and explosive gold . The first description of the laboratory preparation of mercury fulminate is given in Kunkel s book Laboratorium Chymicum published in 1690 [3]. This substance was described again by Howard in 1799-1800 [4]. No further discoveries of other primary explosives were made until the development of modern chemistry. 

Curve A represents the decomposition of mercury fulminate irradiated with ultra-violet rays, curve B the decomposition of ground mercury fulminate, and curve C the decomposition of ordinary (freshly-prepared) mercury fulminate. 

Among other fulminates, the silver salt, (CNO)2Ag, is of some importance. It is prepared in a way similar to mercury fulminate, by the action of alcohol on a silver solution in nitric acid. Silver fulminate, however, is of little value as an explosive since silver is an expensive raw material. Detonators of silver fulminate were employed only in the Italian Navy. 

The other fulminates are of no practical value. They are prepared from mercury fulminate either by reacting the metal amalgam with a suspension of mercury fulminate in water (this is applicable to the majority of metals, including the alkali metals, or simply by the action of the metal itself (e.g. zinc or thallium) which displaces mercury from mercury fulminate (also in water). For example, chips of thallium, zinc, or copper are allowed to stand for some time in a suspension of mercury fulminate in water, the corresponding metal fulminate is gradually formed. 

This substance was the first diazo compound to be discovered. It was prepared by Griess [11] by diazotizing picramic acid. Its explosive properties attracted the attention of Lenze [12] who found it to be as valuable as mercury fulminate in spite of its higher sensitiveness to impact. This compound is also of interest as being the first initiator containing no heavy metals. It has now been utilized in the United States of America and Japan as a component of initiating charges in detonators and caps. 

Mercury fulminate was first prepared in the 17th century by the Swedish-German alchemist, Baron Johann Kunkel von Lowenstern. He obtained this dangerous explosive by treating mercury with nitric acid and alcohol. At that time, Kunkel and other alchemists could not find a use for the explosive and the compound became forgotten until Edward Howard of England rediscovered it between 1799 and 1800. Howard examined the properties of mercury fulminate and proposed its use as a percussion initiator for blackpowder and in 1807 a Scottish Clergyman, Alexander Forsyth patented the device. 

Mercury fulminate is prepared by dissolving mercury in nitric acid and then pouring into ethanol. A vigorous reaction takes pace which is accompanied by the evolution of white fumes, then by brownish-red fumes and finally again by white fumes. At the same time crystals of mercury fulminate are formed. The crystals are recovered and washed with water until all of the acid is removed. 

Medard [23a] examined the explosive properties of methyl-a-D-glucopyranoside tetranitrate prepared according to Fleury et al. [12]. The product requires a relatively weak initiator, e.g. 0.25 g of mercury fulminate suffised to detonate a sample of the substance of density 1.10. Only the cast product (density 1.65) requires a strong detonator (over 1.5 g fulminate). 

The only directly accessible metal fulminates are those of mercury(II) and silver(I), very dangerously exposive solids obtained by the action of nitric acid and ethanol on the metals or their salts. Most modern preparations of fulminato complexes involve the conversion of a known amount of mercury fulminate into aqueous sodium fulminate by the action of sodium amalgam and ice-cold water the sodium fulminate solution is then allowed to react with the appropriate amount of a transition metal salt, and the resulting complex fulminato ion is precipitated as the salt of a large cation, most frequently Ph4As+ or R4N+ these are not explosive,4,35 Alkali and alkaline earth metal salts containing complex fulminato anions may be isolated from aqueous solutions, but they are reported to be as exposive as the binary silver and mercury fulminates, and are therefore usually avoided. 

Mercury fulminate appears to have been prepared for the first time by Johann Kunckel von Lowenstern (1630-1703), the same chemist who discovered phosphorus and applied the purple of... 

The commercial preparation of mercury fulminate is carried out by a process which is essentially the same as that which Howmrd originally recommended. Five hundred or 600 grams of mercury is used for each batch, the operation is practically on the laboratory scale, and several batches are run at the same time. Since the reaction produces considerable frothing, capacious glass balloons are used. The fumes, which are poisonous and inflammable, are passed through condensers, and the condensate, which contains alcohol, acetaldehyde, ethyl nitrate, and ethyl nitrite, is utilized by mixing it with the alcohol for the next batch. 

Preparation of Mercury Fulminate. Five grams of mercury is added to 35 cc. of nitric acid (specific gravity 1.42) in a 100-cc. Erlenmeyer... 

Tolunitrile has also been prepared from o-toluidine by conversion into o-tolyl isothiocyanate and the boiling of this under a reflux condenser 4 />-tolunitrile has been prepared by distilling />-toluic acid with potassium thiocyanate 5 and a mixture of the two has been produced by the interaction of toluene, mercury fulminate, and aluminium chloride.6... 

Mercury fulminate is prepared by dissolving mercury in nitric acid, after which the solution is poured into 95 % ethanol. After a short time, vigorous gas evolution takes place and crystals are formed. When the reaction is complete, the crystals are filtered by suction and washed until neutral. The mercury fulminate product is obtained as small, brown to grey pyramid-shaped crystals the color is caused by the presence of colloidal mercury. 

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