Tetrazene

Tetrazene or tetrazolyl guanyltetrazene hydrate (C2H8N10O) (2.5) was first prepared by Hoffmann and Roth in 1910 by the action of a neutral solution of sodium nitrite on aminoguanidine salts. In 1921, Rathsburg suggested the use of tetrazene in explosive compositions. 

Tetrazene is slightly hygroscopic and stable at ambient temperatures. It hydrolyses in boiling water evolving nitrogen gas. Its ignition temperature is lower than that for mercury fulminate and it is slightly more sensitive to impact than mercury fulminate. 

The detonation properties of tetrazene depend on the density of the material, i.e. its compaction. Tetrazene will detonate when it is not compacted but when pressed it produces a weaker detonation. These compaction properties make the transition from burning to detonation very difficult. Therefore, tetrazene is unsuitable for filling detonators. Tetrazene is used in ignition caps where a small amount is added to the explosive composition to improve its sensitivity to percussion and friction. Some of the properties of tetrazene are given in Table 2.6. 

Structure (2.12) l-(5-Tetrazolyl)-4-guanyl tetrazene hydrate (tetrazene) 

Dinitrobenzene diazo-oxide reacts with hydrazine hydrate to yield 2,4-dinitro-6-[tetrazene-(l)]-phenolhydrazine salt (XIV) 

The product (XIV) can form metal salts. Some of them (e.g. potassium salt) possess initiating properties [24], 

The course of the reaction in the presence of inorganic acids is different from that in the presence of acetic acid. 

Hoffmann etal. [26] suggested the structural formula (la) for tetrazene, i.e. l-guanyl-4-nitrosoaminoguanyltetrazene. The correctness of this formula was later questioned by Patinkin, Horwitz and Lieber [27]. The synthesis of tetrazene by the action of tetrazolediazonium hydroxide (II) on aminoguanidine salts (III) at 0°C, suggested that tetrazene has the structure of l-(5-tetrazolyl)-4-guanyltetrazene hydrate (I)  

The silver salts of (I) to (IV) are white crystalline substances, sparingly soluble in water and organic solvents, but soluble in aqueous ammonia. The initiating efficiency was determined as the smallest amount of the salt needed for initiation of RDX in tubing of a number 8 detonator. The details of the procedure are reported by Avanesov [7]. The experimental values of the minimal amount increases in the following order  

The salts of 1- and 2-(V-nitramino)tetrazole have much better initiating efficiency than their 5-(V-nitramino)tetrazole analogs. The silver salt of 2- N-nitramino)tetrazole (II) is a powerful initiating explosive with efficiency higher than LA [8]. 

Tetrazene crystallizes as a monohydrate in the form of a fluffy solid made up of colorless or pale yellow crystals [12-15] (see Fig. 8.1) with crystal density 1.64—1.65 g cm [15, 16] or 1.7 g cm [13, 16]. The bulk density of GNGT is very low, only 0.45 g cm according to Rinkenbach and Burton [15], Meyer s encyclopedia reports oidy 0.3 g cm [16]. 

Tetrazene is practically insoluble in water and most common organic solvents (alcohol, acetone, ether, benzene, ethylene dichloride). It is slightly hygroscopic as it absorbs 0.77% water (at 30 °C 90% relative humidity). In boiling water, GNGT decomposes [14,16,17]. GNGT does not react with concentrated ammonia, metals (steel, copper, aluminum) or high explosives (TNT, tetryl, PETN, RDX) at room 

The poor thermal stability (it explodes at 135-140 °C [15]) along with its tendency to become easily dead-pressed are some of its drawbacks. 

---

Property Mercury fiihninate Lead azide Silver azide Normal lead styphnate DDNP Tetrazene... 

Solutions of colourless pyrazolidinediones give highly coloured solutions of radicals (113) when treated with lead dioxide. The ESR spectra of these radicals have been recorded (78JOC808). They dimerize to tetrazenes (114) which appear to be indefinitely stable. 

Hetero Diels-Alder reaction of active olefins (enamines) with triazenes, tetrazenes with loss of Nz and formation of new N-heterocycies. 

N4H4 rra 5-2-tetrazene, H2N-N=N-NH2, (colourless, low-melting ciystals, N-N 143pm, N=N 121pm). and ammonium azide, NH4N3 (white ciystals, subl. 133°C, d 1.350gcm 3)... 

Uses It can be used as a secondary charge in detonators replacing Tetryl. Mixts with Diaz onitrophenol (Encycl 2, B59) or Tetrazene... 

C6H4Br.N N.N(C6Hs).N N.N(C6Hs).N N.C6H4Br, pale yel substance, mp 60°. Can be prepd by treating a cold ethereal soln of 3-phenyl-l-[4-bromphenyl]-tetrazene-(l) with a 1% soln of K permanganate (Refl). It is an expl... 

Expls may be classified both from the chemical point of view and according to their uses. From the chemical viewpoint we distinguish between chemical individual substances and mixts. The former are divided into (1) nitro compds, (2) nitric esters, (3) nitramines, (4) derivatives of chloric and perchloric acids, (5) azides, and (6) various compds capable of pro-during an expln, for example fulminates, acetyl-ides, nitrogen rich compds such as tetrazene, peroxides and ozonides, etc... 

Compounds with the classical nonsystematic name diazoamino compound (R-N2NRiR2) and their (logical) derivatives with two or more adjacent nitrogen atoms are considered as substitution products of triazene (NH2 — N=NH), 1-tetrazene, etc. (Rule 942.1). Simple examples are 3-methyltriazene (CH3-NH-N = NH) and 3-methyl-l-tetrazene [NH2-N(CH3)-N = NH]. The classical name is retained only for compounds containing the same group R at each end of an - N=N - NH - group (Rule C-942.2), e. g., A-methyldiazoaminobenzene,... 

In contrast to the addition products of hydrazines, the interaction of arenediazonium ions with acid hydrazides (Scheme 6-18) yields tetrazenes (6.26), which can be isolated. Tetrazoles (6.27) are obtainable by cyclization (Dimroth and de Mont-mollin, 1910). 

Triazene lassen sich durch Lithiumalanat nicht reduzieren3. Tetramethyl-tetrazen liefert mit Trimethyl-amin-alurninium-hydrid Dimethylamino-aluminium-hydrid und Trimethylamin, ... 

Keywords Valence electron rule, Metal ring, Metal cluster, AN +2 valence electron rule, 8/V +6 valence electron rule, 6N +14 valence electron rule, Pentagon stability, Cyclopentaphosphane, Hydronitrogen, Polynitrogen, Triazene, 2-Tetrazene, Tetrazadiene, Pentazole, Hexazine, Nitrogen Oxide, Disiloxane, Disilaoxirane, 1,3-Cyclodisiloxane, Metallacycle, Inorganic heterocycle... 

The delocalization of lone pair electrons on NH group to an adjacent N=N bond was suggested by some calculations [97] to be appreciable in triazene 12 and 2-tetrazene 13. The N-N single bond is shorter than the isolated N-N single bond in NH NH. The N=N bond is longer than in NH=NH. The n-n conjngation stabilizes hydronitrogens. 

Diazonium salts add to active methylene compounds, for example ethyl acetoacetate, to form an intermediate azo compound (22), followed by the addition of a second diazonium salt (under more alkaline conditions) to yield the tetrazene (23) which then forms a 3-substituted formazan (24)10... 

Disubstituted tetrazoles are conveniently prepared from acyl hydrazines (98) and diazonium salts.166 The reaction proceeds through the intermediate tetrazenes (99) followed by cyclization to the tetrazole (100) (Scheme 13). The intermediate can be isolated under mildly basic conditions. Symmetrically 1,2-diacylated hydrazines yield 1-substituted tetrazoles through the elimination of one of the acyl groups.166 - 168 Diformyl-hydrazine is a very convenient starting material for 1-substituted tetrazoles.166, Unsymmetrically 1,2-diacylated hydrazine usually results in mixtures.169... 

Diazonium salts react with bis(methylsulfonyl) methane (107) (X = S02CH3) to yield a 1,3-diaryl tetrazolinone (111). The reaction proceeds through an azo (108) and a tetrazene (109) intermediate, followed by hydrolysis under the alkaline conditions of the reaction to the carbonyl compound (110). An unexplained oxidation leads to the 1,3-diaryl tetrazolinone (111) either directly or through the intermediate 110a (Scheme 15).18,35 A similar reaction occurs between a diazonium salt and the potassium salt of phenyl hydrazonomethane disulfonic acid (Scheme 15).175... 

Tetrazene was discovered by Hofmann and Roth in 1910 and the structure determined by Duke. It is made by the action of sodium nitrite on aminoguanidine sulphate or nitrate under slightly acid conditions. 

Tetrazene is a light yellow crystalline substance, insoluble in water and most organic solvents. The density is low under normal conditions, but on pressing can reach approximately 1 g ml-1. Tetrazene is weak as an initiating explosive, and is therefore not used alone. It has no advantages to commend it for use in commercial detonators, but does find application in the manufacture of military and other percussion caps. Like diazodinitrophenol, tetrazene does not detonate when ignited in the open, but only when ignited under confinement. 

See other perchlorate salts of nitrogenous bases, tetrazenes... 

See other high-nitrogen compounds, tetrazenes, tetrazoles... 

---