New Nitriminotetrazoles – Synthesis, Structures and Characterization

Abstract

The reactions of 5‐nitriminotetrazole (4) with 1‐methyl‐5‐aminotetrazole (2) as well as 2‐methyl‐5‐aminotetrazole (3) were investigated. In the first reaction 2 was protonated yielding 1‐methyl‐5‐aminotetrazolium 5‐nitrimino‐1H‐tetrazolate monohydrate (7). In the latter case no protonation could be observed and a co‐crystallization of 5‐nitraminotetrazole and 2‐methyl‐5‐aminotetrazole was obtained. In this compound a new tautomer of 4 could be found. Both products were determined by low temperature single crystal X‐ray diffraction, IR, Raman and multinuclear (1H, 13C, 15N) NMR spectroscopy, elemental analysis as well as differential scanning calorimetry. In addition the heats of formation were calculated using experimentally obtained heats of combustion. With these and the X‐ray densities several detonation parameter were computed using the EXPLO5 software. In addition the sensitivities towards impact, friction and electrostatic discharge were determined. Further, two crystal structures of the important starting materials in energetic research 5‐nitriminotetrazole monohydrate (4·H2O) and 1‐methyl‐5‐nitriminotetrazolemonohydrate (5·H2O) are presented and compared with the water‐free compounds. The heats of formation of 4, 4·H2O, 5, 5·H2O have been calculated by the atomization method using the CBS basis set. Inclusion of crystal water decrease heats of formation about 265 kJ mol−1. Also the influence of crystal water on sensitivities (impact, friction, electrostatic discharge) but also performance is discussed.

5-(Fluorodinitromethyl)-2H-tetrazole and its tetrazolates – Preparation and Characterization of New High Energy Compounds

“…4 For energetic materials applications, tetrazole is usually further functionalized with explosophore groups such as nitro, N-nitro, azo, or azido. [5][6][7][8][9][10][11][12][13][14][15] In recent years, much effort in energetic materials research was dedicated to the synthesis of novel energetic highly overoxidized compounds that can be used to replace ammonium perchlorate as high-oxygen carrier in solid rocket propellant formulations. An expression that is often being used in order to indicate the degree of oxidation of a compound is the oxygen balance (OB).…”

4‐Nitramino‐3,5‐dinitropyrazole‐Based Energetic Salts

“…These functional groups include -NO 2 (-CNO 2 , -NNO 2 , and -ONO 2 ), -N 3 , -N=N-, -NF 2 , and so forth. [3] Based on density and oxygen balance that are greatly enhanced by the nitro group, [4] nitro-based energetic compounds are always interesting, and many nitro-based highperformance explosives have been developed and applied, such as cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX; P: 35.2 GPa; vD: 8977 ms À1 ), cyclo-1, 3,5,4,6,P: 39.6 GPa;vD: 8977 ms À1 ), and 2,4, 6,8,10,12-(hexanitrohexaaza)tetracyclododecane (CL-20; P: 48.2 GPa; vD: 10 065 ms À1 ). However, energetic materials with high detonation performance often exhibit poor sensitivities, for example, RDX, HMX, and CL-20 with impact sensitivities (IS) as low as 7.4, 7.4, and 4 J, respectively, which tend to restrict their applications.…”

“…However, energetic materials with high detonation performance often exhibit poor sensitivities, for example, RDX, HMX, and CL-20 with impact sensitivities (IS) as low as 7.4, 7.4, and 4 J, respectively, which tend to restrict their applications. Although impact sensitivity can be decreased by replacing the energetic groups with amino groups, the corresponding detonation performance is impacted negatively, for example, 5-nitrotetrazole (P: 39.0 GPa; vD: 9457 ms À1 ; IS: < 1 J), [5] 5-nitraminotetrzole (P: 39.4 GPa; vD: 9450 ms À1 ; IS: 1.5 J), [6] and 5-azidotetrazole (P: 32.7 GPa; vD: 8986 ms À1 ; IS: < 1 J), [7] which are much more energetic than 5-aminotetrazole (P: 24.0 GPa; vD: 8023 ms À1 ; IS: > 40 J). [8] The development of high performance energetic compounds with low sensitivity continues to be a challenging task.…”

RETRACTED: Frictional properties of single crystals HMX, RDX and PETN explosives

“…Frictional rubbing can occur between explosive crystals and a containing wall [3], between individual crystals, and between crystals and inert grits [4][5][6]. Friction between two surfaces, grit particles, or material grains has been studied [7,8].…”