Derivatives of 1,5-Diamino-1H-tetrazole:  A New Family of Energetic Heterocyclic-Based Salts

Abstract

1,5-Diamino-1H-tetrazole (2, DAT) can easily be protonated by reaction with strong mineral acids, yielding the poorly investigated 1,5-diaminotetrazolium nitrate (2a) and perchlorate (2b). A new synthesis for 2 is introduced that avoids lead azide as a hazardous byproduct. The reaction of 1,5-diamino-1H-tetrazole with iodomethane (7a) followed by the metathesis of the iodide (7a) with silver nitrate (7b), silver dinitramide (7c), or silver azide (7d) leads to a new family of heterocyclic-based salts. In all cases, stable salts were obtained and fully characterized by vibrational (IR, Raman) spectroscopy, multinuclear NMR spectroscopy, mass spectrometry, elemental analysis, X-ray structure determination, and initial safety testing (impact and friction sensitivity). Most of the salts exhibit good thermal stabilities, and both the perchlorate (2b) and the dinitramide (7c) have melting points well below 100 degrees C, yet high decomposition onsets, defining them as new (7c), highly energetic ionic liquids. Preliminary sensitivity testing of the crystalline compounds indicates rather low impact sensitivities for all compounds, the highest being that of the perchlorate (2b) and the dinitramide (7c) with a value of 7 J. In contrast, the friction sensitivities of the perchlorate (2b, 60 N) and the dinitramide (7c, 24 N) are relatively high. The enthalpies of combustion (Delta(c)H degrees ) of 7b-d were determined experimentally using oxygen bomb calorimetry: Delta(c)H degrees (7b) = -2456 cal g(-)(1), Delta(c)H degrees (7c) = -2135 cal g(-)(1), and Delta(c)H degrees (7d) = -3594 cal g(-)(1). The standard enthalpies of formation (Delta(f)H degrees ) of 7b-d were obtained on the basis of quantum chemical computations using the G2 (G3) method: Delta(f)H degrees (7b) = 41.7 (41.2) kcal mol(-)(1), Delta(f)H degrees (7c) = 92.1 (91.1) kcal mol(-)(1), and Delta(f)H degrees (7d) = 161.6 (161.5) kcal mol(-)(1). The detonation velocities (D) and detonation pressures (P) of 2b and 7b-d were calculated using the empirical equations of Kamlet and Jacobs: D(2b) = 8383 m s(-)(1), P(2b) = 32.2 GPa; D(7b) = 7682 m s(-)(1), P(7b) = 23.4 GPa; D(7c) = 8827 m s(-)(1), P(7c) = 33.6 GPa; and D(7d) = 7405 m s(-)(1), P(7d) = 20.8 GPa. For all compounds, a structure determination by single-crystal X-ray diffraction was performed. 2a and 2b crystallize in the monoclinic space groups C2/c and P2(1)/n, respectively. The salts of 7 crystallize in the orthorhombic space groups Pna2(1) (7a, 7d) and Fdd2 (7b). The hydrogen-bonded ring motifs are discussed in the formalism of graph-set analysis of hydrogen-bond patterns and compared in the case of 2a, 2b, and 7b.

C2N14 – ein energetisches und höchst empfindliches binäres Azidotetrazol

“…Um die Dimerisierung und den darauf folgenden Ringschluss zu initiieren, wird die saure Reaktionsmischung mit 0.1m Natronlauge langsam auf pH 8 eingestellt. [11] Die basischen Reaktionsbedingungen sind im Zuge der Aufarbeitung sehr wichtig, da sonst auch die Gefahr besteht, dass die Azidsubstituenten partiell von unverbrauchtem Natriumnitrit zu Aminen zersetzt werden. 1 kann anschließend mit Diethylether aus der Reaktionslösung extrahiert und nachfolgend säulenchromatographisch mit Chloroform als Laufmittel von den genannten Zersetzungsprodukten befreit werden.…”

Energetic Nitrogen Rich Salts of N,N‐bis[1(2)H‐Tetrazol‐5‐yl]amine

“…The proton affinities (P A ) were calculated using the G2 method or taken from the literature. [22] A value of 1530.1 kJ mol -1 was adopted for DH f°( H + , 298 K). [23,24] Heats of formation of NH 3 , NH 2 NH 2 and guanidine in the gas phase are available (-45.9, 95.4, and 26.0 kJ mol -1 , respectively).…”

“…[23,24] Heats of formation of NH 3 , NH 2 NH 2 and guanidine in the gas phase are available (-45.9, 95.4, and 26.0 kJ mol -1 , respectively). [22] Heats The heats of formation of the remaining cations and Bta anion were determined by using the method of isodesmic reactions (Scheme 3). [23] The enthalpy of reaction (DH r,298°)…”

Electrostatic Potentials, Intralattice Attractive Forces and Crystal Densities of Nitrogen-Rich C,H,N,O Salts

“…For ionic compounds, the analogue of the heat of sublimation is the lattice enthalpy, which is the enthalpy required to separate the lattice into free gas phase ions. Lattice enthalpies are generally much greater than heats of sublimation [23]. For C,H,N,O ionic explosives in which the ions have +1 and −1 charges, the estimated lattice enthalpies are between 100 and 200 (4).…”