Other Fulminates

In contrast to mercury and silver fulminates, most other metallic fulminates are too sensitive, or physically or chemically unstable. Further, their preparation is too expensive and demanding for practical use. Many fulminates are hygroscopic stable when dry but decompose in presence of carbon dioxide when moist (cadmium, copper(I), copper(n), thaUium) [15, 29, 57, 106]. 

Alkaline fulminates—sodium and potassium—are soluble in methanol, not soluble in acetone and ethanol, and insoluble in ether and benzene [39, 107]. Sodium fulminate explosively decomposes by action of sulfuric acid in the same way as MF and SF do [15]. The spontaneous explosion is reported even during drying above sulfuric acid [108]. The density of alkali fulminates is similar to alkali azides sodium fulminate 1.92 g cm and potassium fulminate 1.80 g cm [39]. Sodium fulminate forms an anhydride or monohydrate depending on preparation procedure. Alkaline fulminates can be stored for a long time in the form of methanol solutions in the dark. These fulminates are hygroscopic they are not stable in contact with moisture and quickly decompose when wet (white color changes to yellow and brown with loss of explosive properties) [15, 107]. Toxicity of sodium fulminate is about the same as that of sodium cyanide [2]. 

Thalhum fulminate is photosensitive it turns yellow under light. It very slowly becomes brown and loses explosive properties on exposure to air (unless sealed in air tight container). Thalhum fulminate is hygroscopic it explosively decomposes by action of sulfuric and nitric acid. It slowly decomposes to a nonexplosive substance on long-term heating [15, 57, 109]. 

Cadmium fulminate forms white crystals that are soluble in alcohol. It is hygroscopic but dry cadmium fulminate is stable (in desiccator above CaCl2) [15]. 

As briefly mentioned in the previous chapter, fulminates are capable of forming a variety of complexes with metals [8, 39]. The first of the fulminato(metal) complexes (complexes with fulminate ligands) was K[Ag(CNO)2]. This compound was obtained by Liebig from the reaction of SF and potassium chloride [8]. Ammonium fulminate NH4CNO has not yet been synthesized. A complex salt containing the ammonium cation NH4[Ag(CNO)2] can be easily prepared by the reaction of the ammonium salt with SF in methanol [39]. 

---

See other fulminating metals, mercury compounds, poly(dimercuryim-... 

Oro fulminance in Ital or Span, Gremucheye zoloto, in Russ). This compd and other fulminating eompds must not be confused with fulminates, described above. Some scientists, accdg to Daniel (Ref I, 314) consider them identical with nitrides (azoeures, in Fr)... 

Fulminating Powders, History. It seems that the earliest discovery dates to the 15th century, when Fulminating Cold (qv) was prepd by Basil Valentin. Discoverers of other fulminating compds are listed under individual compds A resume of description given in the book of Greener (Ref) is given below ... 

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. 

See other FULMINATING METALS, MERCURY COMPOUNDS, N-METAL DERIVATIVES, POLY(DIMERCURYIMMONIUM) COMPOUNDS... 

Mercury Fulminate, and other fulminates, which are now used to a much smaller extent ... 

See other fulminating METALS, mercury compounds, v-metal derivatives... 

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]. 

Other FULMINATE initiators are used as detonators or capsules of many shells or bullets, e.g. Silver fulminate,... fulminate. 

---