New Energetic Materials: Functionalized 1‐Ethyl‐5‐aminotetrazoles and 1‐Ethyl‐5‐nitriminotetrazoles

Abstract

Alkylation of 5-aminotetrazole (1) with 2-chloroethanol leads to a mixture of the N-1 and N-2 isomers of (2-hydroxyethyl)-5-aminotetrazole. Treatment of 1-(2-hydroxyethyl)-5-aminotetrazole (2) with SOCl(2) yielded 1-(2-chlorethyl)-5-aminotetrazole (3). 1-(2-Azidoethyl)-5-aminotetrazole (4) was generated by the reaction of 3 with sodium azide. Nitration of 2, 3, and 4 with HNO(3) (100%) yielded in the case of 2 and 3 1-(2-hydroxyethyl)-5-nitriminotetrazole (5) and 1-(2-chloroethyl)-5-nitriminotetrazole (6). In the case of 4, 1-(2-nitratoethyl)-5-nitriminotetrazole monohydrate (7) was obtained. 1-(2-Azidoethyl)-5-nitriminotetrazole (8) could be obtained by nitration of 4 with NO(2)BF(4) via the formation of potassium 1-(2-azidoethyl)-5-nitriminotetrazolate (9). The reaction of 6 with NaN(3) resulted in the formation of the salt sodium 1-(2-chloroethyl)-5-nitriminotetrazolate (10 a). The deprotonation reaction of 6 was further investigated by the formation of the ammonium salt (10 b). The protonation of 2 and 4 with dilute nitric acid led to 1-(2-hydroxyethyl)-5-aminotetrazolium nitrate (11) and 1-(2-azidoethyl)-5-aminotetrazolium nitrate (12), respectively. Similarly, protonation of 4 with perchloric acid led to 1-(2-azidoethyl)-5-aminotetrazolium perchlorate monohydrate (13). Since 5-nitrimino-tetrazoles can be used as bidentate ligands, the coordination abilities of 5, 6, and 8 were tested by the reaction with copper nitrate trihydrate, yielding the copper complexes trans-[diaquabis{1-(2-hydroxyethyl)-5-nitriminotetrazolato-kappa(2)N(4),O(5)}copper(II)] (14), trans-[diaquabis{1-(2-chloroethyl)-5-nitriminotetrazolato-kappa(2)N(4),O(5)}copper(II)] dihydrate (15), and [diaquabis{1-(2-azidoethyl)-5-nitriminotetrazolato-kappa(2)N(4),O(5)}copper(II)] (16). All compounds were characterized by low-temperature single-crystal X-ray diffraction. In addition, comprehensive characterization (IR, Raman, and multinuclear NMR spectroscopy ((1)H, (13)C), elemental analysis, mass spectrometry, DSC) was performed. The heats of formation of selected compounds were computed by using heats of combustion obtained by bomb calorimetry or calculated by the atomization method. With these values and the densities determined from X-ray crystallography, several detonation parameter were calculated by the EXPLO5 program. Finally, the sensitivities towards impact and friction were determined using a BAM drop hammer and friction tester.

New Energetic Complexes of Copper(II) and the Acetone Carbohydrazide Schiff Base as Potential Flame Colorants for Pyrotechnic Mixtures

“…[10] An alternative application for this class of materials would be flame colorants for use in pyrotechnics. [11][12][13] To this end copper complexes of carbohydrazide should be viable candidates that can be used to generate blue and green flame colors, which are difficult to obtain. This would therefore provide an alternative to the toxic barium salts, which are currently used in pyrotechnics.…”

Two new copper-FOX-7 complexes: synthesis, crystal structure, and thermal behavior

“…As the crystal structure shows in figure 2, a nitrate has coulomb and hydrogen bond interactions with the complex. There are two hydrogen (1) Comparing with other energetic Cu(II) complexes [8][9][10][11][12][13][14][15], we can see that the coordination format of central Cu(II) can form four-coordinated structure [8], five-coordinated structure [9][10][11], and six-coordinated structure [12][13][14][15], according to different ligands and different synthetic conditions. The two new copper-FOX-7 complexes are both five-coordinate.…”

“…Many energetic Cu(II) complexes are used as detonating explosive or combustion catalysts of solid propellant [8][9][10][11][12][13][14][15]. 1,1-Diamino-2,2-dinitroethylene (FOX-7) is a novel high-energy material with high thermal stability and low sensitivity.…”

Quantum chemical studies on three novel 1,2,4-triazole N-oxides as potential insensitive high explosives

“…Seeking and developing novel high explosives with high detonation performance and low sensitivity always have drawn much attention [1][2][3][4][5][6][7][8][9]. However, most of the synthesized or designed new explosives have some obvious shortcomings like low density, low energetic properties, bad thermal stability, high sensitivity, or difficulty of synthesis.…”