Michael D. Coburn

3-Nitro-1,2,4-triazol-5-one, a less sensitive explosive

A less sensitive explosive, 3-nitro-1,2,4-triazol-5-one. The compound 3-nitro-1,2,4-triazol-5-one (NTO) has a crystal density of 1.93 g/cm3 and calculated detonation velocity and pressure equivalent to those of RDX. It can be prepared in high yield from inexpensive starting materials in a safe synthesis. Results from initial small-scale sensitivity tests indicate that NTO is less sensitive than RDX and HMX in all respects. A 4.13 cm diameter, unconfined plate-dent test at 92% of crystal density gave the detonation pressure predicted for NTO by the BKW calculation.

Green primary explosives: 5-Nitrotetrazolato-N2-ferrate hierarchies

The sensitive explosives used in initiating devices like primers and detonators are called primary explosives. Successful detonations of secondary explosives are accomplished by suitable sources of initiation energy that is transmitted directly from the primaries or through secondary explosive boosters. Reliable initiating mechanisms are available in numerous forms of primers and detonators depending upon the nature of the secondary explosives. The technology of initiation devices used for military and civilian purposes continues to expand owing to variations in initiating method, chemical composition, quantity, sensitivity, explosive performance, and other necessary built-in mechanisms. Although the most widely used primaries contain toxic lead azide and lead styphnate, mixtures of thermally unstable primaries, like diazodinitrophenol and tetracene, or poisonous agents, like antimony sulfide and barium nitrate, are also used. Novel environmentally friendly primary explosives are expanded here to include cat[FeII(NT)3(H2O)3], cat2[FeII(NT)4(H2O)2], cat3[FeII(NT)5(H2O)], and cat4[FeII(NT)6] with cat = cation and NT− = 5-nitrotetrazolato-N2. With available alkaline, alkaline earth, and organic cations as partners, four series of 5-nitrotetrazolato-N2-ferrate hierarchies have been prepared that provide a plethora of green primaries with diverse initiating sensitivity and explosive performance. They hold great promise for replacing not only toxic lead primaries but also thermally unstable primaries and poisonous agents. Strategies are also described for the systematic preparation of coordination complex green primaries based on appropriate selection of ligands, metals, and synthetic procedures. These strategies allow for maximum versatility in initiating sensitivity and explosive performance while retaining properties required for green primaries.

An improved synthesis of 5-amino-3-nitro-1H-1,2,4-triazole (ANTA), a useful intermediate for the preparation of insensitive high explosives

Abstract Treatment of the ammonium salt of 3,5-dinitro-1H-1,2,4-triazole (ADNT) with hydrazine hydrate gives 5-amino-3-nitro-1H-1,2,4-triazole (ANTA) in greater than 90% yields. In addition to its potential use as an insensitive high explosive, ANTA has been shown to be a useful intermediate for the preparation of other explosives.

Binary eutectics formed between ammonium nitrate and amine salts of 5-nitrotetrazole I. preparation and initial characterization

Abstract We have found that both the ammonium salt of 5-nitrotetrazole (ANT) and the ethylenediamine salt of 5-nitrotetrazole (ENT) form eutectics with ammonium nitrate (AN). Initial characterization and small-scale sensitivity tests of CO2-balanced AN/ANT and AN/ENT formulations were performed; it was found that both eutectics were less sensitive in all tests than pure ANT or ENT, respectively. The phase diagrams of both mixtures were also determined. ANT forms a eutectic with AN that melts at 121°C; the eutectic composition of the AN/ANT system is 78.5 mol% AN. The eutectic temperature and composition of the AN/ENT system were found to be 110.5°C and 87.8 mol% AN, respectively. Thermal stability studies of the eutectics indicate that they are stable below 160°C and that thermal decomposition occurs slowly over a long period of time. The detonation velocities of both eutectics, measured unconfined at 2.54-cm diameter, were found to be within 95% of those predicted by the Kamlet-Jacobs method assuming ide...

Scale-up and waste-minimization of the Los Alamos process for 1,3,3-trinitroazetidine (TNAZ)

Abstract The original synthesis of TNAZ (1,3,3-trinitroazetidine) was developed by T. G. Archibald in 1983 and was scaled up to produce several hundred kg of TNAZ for evaluation by the DoD. Although the synthesis method utilizes inexpensive starting materials, it is a multi-step process that gives less than 20% overall yields and produces significant chemical waste (over 1200 kg kg −1 of TNAZ), including large quantities of halogenated solvents. An alternative synthesis, which gives much higher yields of TNAZ and less waste than obtained from the original process, was developed at the Los Alamos National Laboratory. The technology was transferred to Aerojet, Sacramento, where it was scaled up to production-plant quantities to give TNAZ in 57% overall yield. The new process produced about 10% of the waste produced in the original process without recycle of solvents or reagents. It is estimated that recycle of solvents and reagents will reduce the chemical waste to 15.7 kg kg −1 of TNAZ. Further improvements in waste reduction have been demonstrated that may eventually lead to a process giving little more than 3.7 kg of chemical waste kg −1 of TNAZ in addition to the energy burden encountered with any industrial process.

Synthesis of 15N-labeled isomers of 5-Nitro-2,4-Dihydro-3H-1,2,4-Triazol-3-One (NTO)

Abstract The synthetic routes to 15N labeled 5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one (NTO) isomers are reported. Isomers labeled on N(6), N(4) and both N(1) and N(2) have been made. These compounds were identified by 1H, 13C, and 15N NMR and by mass spectral analysis. In many cases unequivocal NMR and mass spectral assignments were made.

Synthesis and spectra of some 2H-, 13C-, and 15N-labeled isomers of 1,3,3-trinitroazetidine and 3,3-dinitroazetidinium nitrate

Abstract The title compounds were synthesized by utilizing appropriately labeled starting materials and reagents according to literature procedures.1,2 The products were characterized by NMR and mass spectral analysis. Unequivocal assignments of all NMR chemical shifts of the unlabeled title compounds and their intermediate precursors were facilitated by the NMR spectra of the labeled compounds along with carbon-hydrogen correlation experiments.

Mass Spectral Fragmentation Pathways in 1,3,3-Trinitroazetidine

The electron impact (EI) fragmentation pathways of 1,3,3-trinitroazetidine (TNAZ) along with some 15N and 2H analogs were studied. Collision-induced dissociation was also used to investigate important peaks in the EI spectra. Isotopically labeled compounds allowed the determination of most of the major fragmentation peaks. It was found that the major pathway involves the loss of NO2 or HNO2 from the dinitroalkyl group followed by a loss of NO2 or NO from the nitramine group. The peak at m/z 46, [NO2]+, the base peak, resulted primarily from N—N bond scission while the peak at m/z 30, [NO]+, was equally likely to come from any NO2 bond. The fragmentation pathway of TNAZ showed similarities with other nitramine and nitrocarbon explosives.