A Study of Cyanotetrazole Oxides and Derivatives thereof

Abstract

In this work we report on the syntheses of energetic salts of cyanotetrazolate-1- and -2-oxides; this offers a unique ability to compare the effects of tetrazole 1- versus 2-oxidation. 5-Cyanotetrazolate-2-oxide can be synthesized by oxidation of the 5-cyanotetrazolate anion with Oxone, while the corresponding 1-oxide was synthesized by the rearrangement of azidoaminofurazan. Both chemical (multinuclear NMR, IR, and Raman spectroscopies, mass spectrometry, etc.) as well as explosive (impact, friction, and static sensitivities) properties are reported for these energetic salts. Calculated explosive performances using the EXPLO5 computer code are also reported. We furthermore detail the chemistry of these two anions, and their ability to form tetrazole-carboxamides, dihydrotetrazines, and tetrazines. The ability to hydrolyze cyanotetrazole oxides to their amides was demonstrated by two copper complexes. Several crystal structures of these species are presented in addition to full chemical characterization. Finally, the unique 1,4,-bis(2-N-oxidotetrazolate)-1,2,4,5-tetrazine anion was characterized as an energetic material as its ammonium salt.

5‐(1H‐Tetrazolyl)‐2‐Hydroxy‐Tetrazole: A Selective 2N‐Monoxidation of Bis(1H‐Tetrazole)

“…The replacement of RDX with TKX-50 is still an ongoing research topic, and various compatibility and performance tests must be performed. [22] For 3, the 13 C resonances are found at 148.4 ppm for the carbon in the tetrazole ring with the 2Noxide and 152.4 ppm for the carbon in the tetrazole ring without oxide. The detonation velocity of the acid 3 (8749 m s À1 ) is higher than those of the salts 10 (8635 m s À1 ) and 11 (8239 m s À1 ).…”

“…[23] For compound 2, we observed the characteristic pattern of vibrations in the Raman spectra as described in the literature for other salts of cyanotetrazole-2-oxide. [22] The Raman spectra of compounds 4-11 show absorptions in the range 1540-700 cm À1 , which can be assigned to the vibrations of the tetrazole and the tetrazole-2-oxide rings [n(NN), n(NCN), g(CN), d aromatic ring]. As other characteristic bands, the N3ÀN4 tetrazole stretch is observed at 1014 cm À1 , and the C1ÀN4 stretch arises at 1454 cm À1 .…”

Energetic Complexes of 5‐(4‐Amino‐1,2,4‐triazol‐3‐on‐5‐yl)­tetrazole and Ionic Derivatives of its 2N‐Oxide

“…Furthermore, the typical observed band of the N-oxide of the synthesized salts 2-4 arises at 1533-1530 cm -1 . [23] The carbonyl moiety of the connected triazole ring shows a strong absorption band at 1718-1693 cm -1 and the amino moiety is observed at 3348-3022 cm -1 . [24] The coordination compound 5 shows a sharp band at 3410 cm -1 and a broad one at 3364 cm -1 in the infrared spectrum for the O-H valence vibrations.…”

“…[23] The N-O valence vibration of the N-oxide moiety shows a band at 1034-1022 cm -1 . [25] The band of the carbonyl moiety of the triazolone can be observed in the range from 1656 to 1642 cm -1 .…”

Dissolution thermokinetics of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate in dimethyl sulfoxide

“…The carbon on position 5 of the ring allows the facile attachment of various substituents for energetic tailorability, and the high nitrogen content and heat of formation of the heterocycle lead to high energetic performances [1][2][3]. In order to improve the energetic properties of tetrazoles, several recently published studies show that introduction of N-oxides yields compounds with even higher densities and stabilities, low sensitivities and better oxygen balances [4][5][6][7]. Combining these principles with practical considerations in mind, the high-performing energetic material dihydroxylammonium 5,5 0 -bistetrazole-1,1 0 -diolate (TKX-50) was synthesized [8].…”