Thermoanalysis and crystal structure of Ammonium 4-Amino-3-(5-tetrazolate)-furazan (NH 4 AFT)

Abstract

Ammonium 4-amino-3-(5-tetrazolate)-furazan (NH₄AFT), one of furazan-functionalized tetrazolate-based energetic salts, was prepared by direct acid-base neutralization of 4-amino-3-(5-tetrazole)-furazan and ammonium hydroxide in aqueous solution. The crystal structure was characterized by X-ray single crystal diffraction, and the crystal belongs to triclinic system with space group Pī and a = 7.244(3) nm, b = 7.000(9) nm, c = 7.280(3) nm, α= 104.317(4)°, β= 108.266(5)°, γ= 92.67°, V = 348(433) nm³, and Z = 2. The thermoanalysis, based on differential scanning calorimetry (DSC), showes the temperature of extrapolated onset (T_eo) is 234.8°C. The non-isothermal thermokinetics parameters were also obtained by Kissinger’s method, Ozawa’s method and Starink’s method. And the critical temperature of thermal explosion (T_b), entropy of activation (ΔS^≠), enthalpy of activation (ΔH^≠), and free energy of activation (ΔG^≠) were also calculated.

Keywords

Energetic salt furazan tetrazole crystal structure thermoanalysis

1 Introduction

Nitrogen-rich salts have long been recognized as one class of promising modern energy materials. Salt-based energetic materials often tend to exhibit lower vapor pressures and higher thermal stability than their atomically similar nonionic analogues. Many organic cations and anions deriving from imidazole [1 –3], triazole [1 , 5], furazan [6 –8], tetrazine [9 –11] and tetrazole [12 –14] have been reported, their properties are readily tuned and optimized through independent variation and modification of the cationic and/or anionic components.

Most energy of nitrogen-rich energetic compounds derive from their high positive heats of formation from the large number of inherently energetic N-C, N-N, N = N, N-O, N-B and N-halogen bonds. As reported, some of high-nitrogen heterocyclic compounds [15 –19] have excellent characteristics, including high density (d), positive heat of formation, high detonation velocity (D) and pressure (P), favorable oxygen balance (OB), high thermal stability, low sensitivity, and so on. Tetrazoles [20] have occupied an important position in recently interesting HEDMs. In their molecular structures, there are many N-N, C-N, N = N and C = N bonds, so tetrazoles possess the high-nitrogen content (about 80%), and high positive heat of formation (about 235 kJ·mol⁻¹). What’s more, duing to the aromaticity and conplane structure of tetrazole ring, they also have good thermal stabilities. Decomposition of tetrazoles generates large volume of nitrogen, which makes them be more environmentally friendly in the applications of highly energetic materials. Two energetic compounds (TATA⁺)·(TZA^-)·H₂O and (DAT²⁺)·(NO₃^-)₂ [21], possessing nitrogen contents of 51.42% and 53.80%, have been synthesized and structurally characterized (TATA = 1,3,5-triazine-2,4,6-triamine, TZA = tetrazole-1-acetic, AT = 5-amino-1H- tetrazole). Both of them are insensitive to external stimuli. What’s more, the calculated detonation value (D and P) of (DAT²⁺)·(NO₃^-)₂ (D = 9300.42 m·s^-¹, P = 37.36 GPa) is obviously higher than that of RDX (D = 8748 m·s^-¹, P = 31.2 GPa) and TATB (1,3,5-triamino-2,4,6-trinitrobenzene) (D = 8144 m·s^-¹, P = 31.2 GPa) [21]. A series salts of HANTT [22] (3-nitro-1-(2H-tetrazol-5-yl)- 1H-1,2,4-triazol-5-amine) have excellent thermal stabilities, and most of them are insensitive to impact, friction and electrostatic discharge. Especially, the salt, hydroxylammonium ANTT, is superior to RDX in view of the thermal and mechanical stabilities. And N-ethylene-bridged-5-nitraminotetrazole has competitive properties including density, detonation values, thermal stability, and sensitivity (d = 1.86 g·cm⁻³, P = 38.2 GPa, D = 9329 m·s⁻¹, T_d = 194°C, IS = 10 J) [23]. While there still exists some problems waiting to be solved. Among tetrazoles and their energetic salts, the balance between energy and sensitivity is hard to get to our expectation. Despite high sensitivities, energetic salts, produced from reactions of nitrogen-rich bases and 1,5-di(nitramino)-tetrazole, show detonation performances competitive with that of CL-20 [24]. 5-nitraminotetrazole [23] exhibits good density and detonation performance (d = 1.87 g·cm⁻³, P = 36.3 GPa, D = 9173 m·s⁻¹), but it has poor thermal stability and impact sensitivity (T_d = 122°C, IS = 1.5 J). Considering the high sensitive characteristics of them, increasing the stability is an important problem to be solved. Incorporation of a furazan ring into compounds is a known strategy for increasing thermal stability. In addition, using a cycle-furazan [25 –27] to replace one hydrogen atom of tetrazoles ring, the energetic materials can obtain an improved oxygen balance without losing energy and stability. Modeling studies show that the density, heat of formation and detonation velocity are increased about 0.06∼0.08 g·cm⁻³, 200 kJ·mol⁻¹, and 300 m·s⁻¹, respectively, when a nitro-group is replaced by a furazan-group in energetic compounds [27]. However, the absence of an acidic proton in the furazan ring makes it impossible to act as a cation or an anion in an energetic salt. So it would be significant to combine furazan with tetrazole compounds, which can be deprotonated and converted to the corresponding anions, easily. Thus a furazan-tetrazole compound is favorable for obtaining a higher heat of formation [6 , 29]. To the best of our knowledge, there is only very few structurally characterized compounds containing the 4-amino-3-(5-tetrazolate)-furazan ring can be found. Shreeve et al. [30, 31] reported furazan-functionalized tetrazolate-based salts by the combination of the furazan ring with tetrazole. In those papers, they reported a series of triazolyl- and triazolium-functionalized unsymmetrical energetic salts and they showed some novel properties that could not be obtained through mono-energetic fragments owing to the synergistic effect of two energetic rings. For ammonium 4-amino-3-(5-tetrazolate)-furazan (NH₄AFT), melting point (T_m) and thermal degradation temperature (T_d) are respectively 278.8°C and 289.8°C, which are higher than that of commonly used explosive RDX (T_m = 204 °C, T_d = 230.8°C). The NH₄AFT has a density of 1.62 g·cm⁻³, and it possess negative OB (–75.2%), which are comparable nearly as that of TNT (–74.0%). What’s more, it has higher heat of formation (626.4 kJ·mol⁻¹) [31]. Also, it presented no hypergolic property (added to 100% nitric acid) and insensitivity to impact (with a BAM Fall hammer, in which 10 kg mass was droppedfrom 40 cm) [32].

However, no experimentally determined structural data were presented. Consequently, a report on the preparation of the NH₄AFT adopted a different method, is given in this paper. What’s more, we have studied the thermoanalysis and crystal structure of NH₄AFT.

2 Experimental section

General Caution: NH₄AFT is an energetic compound and tends to explode under certain conditions. Though we haven’t experienced difficulties in the synthetic process, small-scale and appropriate safety precautions (safety glasses, face shield, leather gloves, and so on) should be taken, especially when NH₄AFT is prepared in dry state.

2.1 Materials and physical techniques

The reagents and solvents were all analytically pure commercial products. IR spectra were recorded with KBr plates using a Bruker Equinox 55 infrared spectrometer (KBr pellets) in the range of 4000∼400 cm⁻¹ with a resolution of 4 cm⁻¹. Elemental analyses were performed with a Flash EA 1112 full automatic trace element analyzer. DSC measurements were performed with a Pyris-1 differential scanning calorimeter in a dry nitrogen atmosphere with flowing rate of 20 mL·min⁻¹. The crystal sample was powdered and put in the aluminum pans and open platinum pans, then heated from 30 to 500°C at 5, 10, 15, 20°C·min⁻¹, respectively.

2.2 Synthesis of NH₄AFT

HAFT was easily synthesized through the reaction of malononitrile, sodium nitrite, and hydroxylamine, followed by oxidation with PbO₂, then cycloaddition with NaN₃, as reported [33].

A solution of 30% ammonia hydroxide (0.116 g, 1.0 mmol) was added dropwise to a solution of HAFT (0.153 g, 1.0 mmol) in deionized water (20 mL) and was stirred at 60∼65 °C for 30 min. Then, the resulting solution was cooled to room temperature with incessant stir. The precipitate was collected by filtration, washed twice with ethanol (5 mL), and dried in an explosion-proof water-bath dryer. Single crystals suitable for X-ray measurements were obtained after crystallization from the filtrate. Experiments use ammonia and HAFT in the molar ratios 1:1. Elemental analysis (%) for C₃H₆N₈O: calcd. C 21.18; H 3.55; N 65.86; found: C 21.08; H 3.50; N 65.17. IR(KBr): $\tilde{v}$ = 3424 (w), 3320 (w), 3250 (w), 3164 (w), 2990 (w), 2842 (w), 2194(vw), 1935 (w), 1840 (w), 1698 (m), 1630 (s), 1596 (m), 1566 (w), 1445 (s),1360 (m), 1212 (vw), 1158 (s), 1084 (vw), 1032 (m), 982 (s), 894 (m), 866(m), 772 (w), 712 (vw), 619 (m), 482 cm⁻¹ (w).

2.3 X-ray data collection and structure refinement

The X-ray diffraction data collection was performed with a Rigaku AFC-10/Saturn724⁺ CCD detector diffractometer with graphite monochromated Mo-Kα radiation (λ= 0.71073 Å) with φ and ω modes at 153(2) K. The structure was solved by direct methods using SHELXS-97 [34] and refined by full-matrix least-squares methods on F² with SHELXL-97 [35]. All non-hydrogen atoms were obtained from the difference Fourier map and subjected to anisotropic refinement by full-matrix least-squares on F².

Crystallographic data (excluding structure factors) for the structure in this paper have been deposited with the Cambridge Crystallographic Data Centre, CCDC, 12 Union Road, Cambridge CB21EZ, UK. Copies of the data can be obtained free of charge on quoting the depository number CCDC-1443631.

3 Results and discussion

3.1 X-ray crystallography

A crystal of NH₄AFT suitable for X-ray diffraction was obtained by slow evaporating from an aqueous solution at room temperature.

The NH₄AFT contains one 4-amino-3-(5-tetrazolate)-furazan anion (AFT^-) and one ammonium cation without crystal water. The single crystal structure of NH₄AFT was determined by applying X-ray single crystal diffraction, which shows that the crystal belongs to triclinic crystal system with space group Pī, and its crystal parameters: a = 7.244(3) nm, b = 7.000(9) nm, c = 7.280(3) nm, α= 104.317(4)°, β= 108.266(5)°, γ= 92.67°, V = 348(433) nm³, and Z = 2. Its experimental density is 1.622 g·cm⁻³ (calculated 1.61 g·cm⁻³ [31]). The structure is shown in Fig. 1. The packing structure along c axis of the unit cell is shown in Fig. 2. The crystallographic and structural refinement data are listed in Table 1. The bond lengths and bond angles are shown in Table 2.

As shown in Fig. 1, the unit cell consists of one ammonium cation and one HAFT anion. According to Table 2, the N-N bond lengths in the tetrazolate rings of it [1.300(3)–1.300(13) Å], are between N-N single bonds (1.454 Å) and N = N double bonds (1.245 Å). The C1-C2 bond and C2-C3 bond are 1.500(9) Å and 1.400(14) Å, respectively. The O1-N5 [1.400(13) Å] bond is longer than the O1-N6 [1.400(7) Å] bond, which indicates that the O1-N5 bond may be the trigger bond of decomposition. In the HAFT anion, the bond lengths of the tetrazole ring range from 1.300(3) Å to 1.343(4) Å [N1-C1] with an average value of 1.308 Å, which is 0.038 Å longer than the normal C = N bond length (1.270 Å), 0.056 Å longer than the normal N = N bond length of 1.252 Å and 0.162 Å shorter than the normal N-N bond length of 1.470 Å. The bond lengths of the furazan ring range from 1.300(4) Å [N6-C3] to 1.400(14) Å [C2-C3] with an average value of 1.361 Å, which is 0.091 Å longer than the normal C = N bond length (1.270 Å), 0.109 Å longer than the normal N = N bond length of 1.252 Å and 0.109 Å shorter than the normal N-N bond length of 1.470 Å. Additionally, in the title salt the tetrazole ring and the furazan ring lie in different planes, and they are slightly twisted with the dihedral angle between them of 6.6°. The atoms in either tetrazolate or furazan rings are planar with mean deviations from their respective plane of 0.0003, 0.0029 Å. A view along the c axis (Fig. 2) reveals the packing of the anions and cations.

Likewise, ATNF (ammonium 4-nitro-3-(5-tetrazole)-furoxan) [36] is also an energetic salt derived from the combination of tetrazole with furoxan. But parts of its properties can’t match NH₄AFT. For example, its thermal degradation temperature (T_d) is 142°C, which is lower than that of NH₄AFT, and its oxygen balance (OB) is –29.6%, which is higher than that of NH₄AFT. In Table 1, the crystallographic and the structural refinement data of ATNF is also listed as a contrast.

The hydrogen bonds lengths and angles are summarized in Table 3. In the crystal structure, there are three types of intra-molecular hydrogen bonds. The first occurs between the nitrogen atom of the furazan ring and the nitrogen atom of the amino in AFT^- (N7-H7A···N6). The second occurs between the nitrogen atom of the tetrazolate groups and the nitrogen atom of the amino in AFT^- (N7-H7B···N1). The third occurs between the nitrogen atom of the amino group and the nitrogen atoms of tetrazolate group (N8-H8A···N2, N8-H8B···N3, N8-H8C···N4, N8-H8D···N1). Since the amino groups in both AFT^- and ammonium are excellent hydrogen-bonding donors, the discrete AFT^- and ammonium are linked into a 2D double layer by the hydrogen-bonding interactions between cations and anions. It can be seen from the packing diagram (Fig. 2).

3.2 Thermal decomposition

In order to investigate the thermal behaviors, DSC curves of NH₄AFT with the linear heating rate of 5, 10, 15, 20°C·min⁻¹ were recorded in a nitrogen atmosphere (Fig. 3). Each DSC curve shows that there are one endothermic peak and one exothermic peak, and the exothermic peak with the onset temperature ranged from 234.6°C, 234.8°C, 235.1°C, 235.5°C, respectively, and the peak temperature ranged from 260.2°C, 270.6°C, 275.6°C, 285.2°C, severally.

3.3 Non-isothermal kinetics analysis

In the presented works, Kissinger’s method [37], Ozawa’s method [38] and Starink’s method [39] have widely been used to determine the Arrhenius Equation. $\ln (β / T^{s}) = - (BE / RT) + C$ (1)

Where T is the peak temperature in K. E is the apparent activation energy in kJ·mol⁻¹. R is the gas constant (8.314 J·K⁻¹·mol⁻¹). β is the linear heating rate in °C·min⁻¹. B and C are constant. When s = 2 and B = 1, Equation (1) is according to Kissinger’s method. When s = 0, B = 1.0516, Equation (1) is according to Ozawa’s method. When s = 1.8 and B = 1.0037, Equation (1) is according to Starink’s method.

Based on the first exothermic peak temperatures measured with four different heating rates of 5, 10, 15, and 20°C·min⁻¹, Kissinger’s method, Ozawa’s method, and Starink’s method were applied to study the kinetics parameters of the title compound. Based on the original data and the relationship of ln(β/T_P²), ln(β/T_P^1.8), and lnβ to 1/T_p, corresponding to Kissinger’s method, Starink’s method, and Ozawa’s method, the apparent activation energy E, pre-exponential factor A, linear correlation coefficient R, and standard deviation S were determined and shown in Table 4. Accordingly, the Arrhenius Equation can be expressed as follows: $\ln k = 27.26 - 160.3 \times 10^{3} / RT$ (2)

3.4 Calculation of critical temperature of thermal explosion, ΔS^≠, ΔH^≠ and ΔG^≠

The value of the peak temperature corresponding to β⟶ 0 obtained according to the following Equation (3) [40] is 507.6 K (234.4°C), where a, b and c are coefficients. $T_{pi} = T_{p 0} + a β + b β^{2} + c β^{3}$ (3)

The corresponding critical temperatures of thermal explosion (T_b) obtained is 523.7 K by the following Equation (4) [36], where R is the gas constant, E is the value of E by Kissinger’s method. $T_{b} = (E - \sqrt{E^{2} - 4 {ERT}_{p 0}}) / 2 R$ (4)

The entropy of activation (ΔS^≠), enthalpy of activation (ΔH^≠), and free energy of activation (ΔG^≠) of the decomposition reaction of NH₄AFT corresponding to T = T_p0, E_a = E_K and A = A_K (obtained by Kissinger’s method), obtained by the following Equation (5), Equation (6), and Equation (7) [36] are -51 J·K⁻¹·mol⁻¹,140.7 kJ·mol⁻¹, and 166.6 kJ·mol⁻¹, respectively. $A = (k_{B} T / h) \exp (1 + Δ S^{\neq} / R)$ (5) $Δ H^{\neq} = E - RT$ (6) $Δ G^{\neq} = Δ H^{\neq} - T Δ S^{\neq}$ (7)

Where k_B is the Boltzmann constant (1.381×10⁻²³ J·K⁻¹) and h is the Planck constant (6.626×10⁻³⁴ J·s).

4 Conclusions

Nitrogen-rich and highly thermally stable HATF and ATF-based energetic salt, NH₄AFT, were successfully synthesized and fully characterized. Combining the properties of a furazan fragment and a tetrazolate backbone, NH₄AFT possesses high densities (1.622 g·cm⁻³) and shows high thermal stabilities (289.8°C) with relative energetic properties, compared with those of the conventional explosives, such as TATB and RDX. So it can be classified as one of promising insensitive energy materials.

Footnotes

Acknowledgments

This work was supported by the project supported by Science Foundation of North University of China and Chongqing Key Laboratory of Inorganic Special Functional Materials (Yangzte Normal University, No. KFKT201503).

References

Yin

, He

C.L.

and Shreeve

J.M.

, Fused heterocycle-based energetic salts: Alliance of pyrazole and 1,2,3-triazole, J Mater Chem A 4 (2016), 1514–1519.

Braunschweig

, Ewing

W.C.

, Kramer

, et al. Organometallic probe for the electronics of base-stabilized group 11 metal cations, Chem Eur J 21 (2015), 12347–12356.

Huang

, Qi

, Zhang

, et al. Exploring sustainable rocket fuels:[imidazolyl-amine- BH₂]⁺-cation-based ionic liquids as replacements for toxic hydrazine derivatives, Chem Asian J 10 (2015), 2725–2732.

Z.H.

, Bi

Y.G.

, Feng

Y.A.

, et al. Synthesis, structure, and characterization of 3,4′-bis-1H -1,2,4-triazolium picrate salt: A new high-energy density material, Anorg Allg Chem 4 (2016), 317–322.

Ghosh

and Bhattacharya

, Prediction of electronically nonadiabatic decomposition mechanisms of isolated gas phase nitrogen-rich energetic salt: Guanidium-triazolate, Chem Phys 464 (2016), 26–39.

, Liu

X.Y.

, Zhang

, et al. A low sensitivity energetic salt based on furazan derivative and melamine: Synthesis, structure, density functional theory calculation, and physicochemical property, J Chem Eng Data 61 (2016), 207–212.

, Zhao

F.Q.

, Wang

B.Z.

, et al. A new family of energetic salts based on oxy-bridged bis- (dinitromethyl) furazan: Syntheses, characterization and properties, RSC Adv 5 (2015), 21422–21429.

Klapötke

T.M.

, Schmid

P.C.

and Stierstorfer

, Crystal structures of furazanes, Crystals 5 (2015), 418–432.

Chavez

D.E.

, Bottaro

J.C.

, Petrie

, et al. Synthesis and thermal behavior of a fused, tricyclic 1,2,3,4-tetrazine ring system, Angew Chem Int Ed 54 (2015), 12973–12975.

10.

Aizikovich

, Shlomovich

, Cohen

, et al. The nitration pattern of energetic 3,6-diamino-1,2,4,5-tetrazine derivatives containing azole functional groups, Dalton Trans 44 (2015), 13939–13946.

11.

Ghule.

V.D.

, Computational screening of nitrogen-rich energetic salts based on substituted triazine, J Phys Chem C 117 (2013), 16840–16849.

12.

Zhao

Z.H.

, Du

Z.M.

, Han

Z.Y.

, et al. Nitrogen-rich energetic salts: Both cations and anions contain tetrazole rings, J Energ Mater 34 (2016), 183–196.

13.

Gao

X.N.

, An

, Li

J.Z.

, et al. Ferrocenyl ionic compounds based on 5-ferrocenyl-1H- tetrazole. synthesis, characterization, migration, and catalytic effects during combustion, Z Anorg Allg Chem 642 (2016), 155–162.

14.

Dippold

A.A.

, Izsák

, Klapötke

T.M.

, et al. Combining the advantages of tetrazoles and 1,2,3-triazoles:4,5-bis(tetrazol-5-yl)-1,2,3-triazole,4,5-bis(1-hydroxytetrazol-5-yl)-1,2,3- triazole, and their energetic derivatives, Chemistry 5 (2016), 1768–1778.

15.

Gao

and Shreeve

J.M.

, Azole-based energetic salts, Chem Rev 111 (2011), 7377–7436.

16.

Dippold

A.A.

and Klapötke

T.M.

, A study of dinitro-bis-1,2,4-triazole-1,1′-diol and derivatives: Design of high-performance insensitive energetic materials by the introduction of N-oxides, J Am Chem Soc 135 (2013), 9931–9938.

17.

Song

J.H.

, Zhou

Z.M.

, Dong

, et al. Super-high-energy materials based on bis-(2,2- dinitroethyl)-nitramine, J Mater. Chem 22 (2012), 3201–3209.

18.

Thottempudi

and Shreeve

J.M.

, Synthesis and promising properties of a new family of high-density energetic salts of 5-nitro-3-trinitromethyl-1H-1,2,4-triazole and 5,5′-bis(trinitromethyl)-3,3′-azo-1H-1,2,4-triazole, J Am Chem Soc 133 (2011), 19982–19992.

19.

Fischer

, Fischer

, Klapötke

T.M.

, et al. Pushing the limits of energetic materials–the synthesis and characterization of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate, J Mater Chem 22 (2012), 20418–20422.

20.

Zhang

Q.H.

, Zhang

J.H.

, Parrish

D.A.

, et al. Energetic N-trinitroethyl-substituted mono-, di-, and triaminotetrazoles, Chem Eur J 19 (2013), 11000–11006.

21.

Zhang

, Liu

X.Y.

, L

, et al. A new strategy for storage and transportation of sensitive high-energy materials: Guest-dependent energy and sensitivity of 3D metal-organic-framework-based energetic compounds, Cryst Eng Comm 20 (2014), 7906–7910.

22.

Bian

C.M.

, Zhang

, Li

, et al. 3-Nitro-1-(2H-tetrazol-5-yl)-1H-1,2,4-triazol-5-amine (HANTT) and its energetic salts: Highly thermally stable energetic materials with low sensitivity, J Mater Chem 3 (2015), 163–169.

23.

Yin

, Zhang

Q.H.

and Shreeve.

J.M.

, Dancing with energetic nitrogen atoms: Versatile N-functionalization strategies for N-heterocyclic frameworks in high energy density materials, Acc Chem Res 49 (2016), 4–16.

24.

Fischer

, Klapötke

T.M.

and Stierstorfer

, 1,5-Di (nitramino) tetrazole: High sensitivity and superior explosive performance, Angew Chem Int Ed 54 (2015), 10299–10302.

25.

Zhang

J.H.

and Shreeve

J.M.

, 3,3′-Dinitroamino-4,4′-azoxyfurazan and its derivatives: An assembly of diverse N-O building blocks for high-performance energetic materials, J Am Chem Soc 136 (2014), 4437–4445.

26.

Fischer

, Klapötke

T.M.

, Reymann

, et al. Dense energetic nitraminofurazanes, Chem Eur J 20 (2014), 6401–6411.

27.

Qiu

H.W.

, Stepanov

, Di Stasio

A.R.

, et al. RDX-based nanocomposite microparticles for significantly reduced shock sensitivity, J Hazard Mater 185 (2011), 489–493.

28.

Zhang

J.H.

, Mitchell

L.A.

, Parrish

D.A.

, et al. Enforced layer-by-layer stacking of energetic salts towards high-performance insensitive energetic materials, J Am Chem Soc 137 (2015), 10532–10535.

29.

Wei

, Zhang

J.H.

, He

C.L.

, et al. Energetic salts based on furazan-functionalized tetrazoles: Routes to boost energy, Chem Eur J 21 (2015), 8607–8612.

30.

Wei

, He

C.L.

, Zhang

J.H.

, et al. Combination of 1,2,4-oxadiazole and 1,2,5-oxadiazole moieties for the generation of high-performance energetic materials, Chem Eur J 127 (2015), 9499–9503.

31.

Wang

R.H.

, Guo

, Zeng

, et al. Furazan-functionalized tetrazolate-based salts: A new family of insensitive energetic materials, Chem Eur J 15 (2009), 2625–2634.

32.

Schneider

, Hawkins

, Rosander

, et al. Ionic liquids as hypergolic fuels, Energy & Fuels 22 (2008), 2871–2872.

33.

Liang

L.X.

, Wang

, Bian

C.M.

, et al. 4-Nitro-3-(5-tetrazole)furoxan and its salts: Synthesis, characterization, and energetic properties, Chem Eur J 19 (2013), 14902–14910.

34.

Kissinger.

H.E.

, Reaction kinetics in differential thermal analysis, Anal Chem 29 (1957), 1702–1706.

35.

Ozawa.

, A new method of analyzing thermogravimetric data, Bull Chem Soc Jpn 38 (1965), 1881–1886.

36.

Boswell.

P.G.

, On the calculation of activation energies using a modified Kissinger’s method, J Therm Anal Calorim 18 (1980), 353–358.

37.

Zhang

T.L.

, Hu

R.Z.

, Xie

, et al. The estimation of critical temperatures of thermal explosion for energetic materials using non-isothermal DSC, Thermochim Acta 244 (1994), 171–176.

38.

Gálvez-Ruiz

J.C.

, Holl

, Karaghiosoff

, et al. Derivatives of 1,5-diamino-1H-tetrazole: A new family of energetic heterocyclic-based salts, Inorg Chem 44 (2005), 4237–4253.

39.

Sheldrick

G.M.

, SHELXS-97, Program for the Solution of Crystal Structures, University of Göttingen, Germany, 1990.

40.

Sheldrick

G.M.

, SHELXL-97, Program for Crystal Structure Refinement from Diffraction Data, University of Göttingen, Germany, 1997.

Thermoanalysis and crystal structure of Ammonium 4-Amino-3-(5-tetrazolate)-furazan (NH 4 AFT)

Abstract

Keywords

1 Introduction

2 Experimental section

2.1 Materials and physical techniques

2.2 Synthesis of NH4AFT

2.3 X-ray data collection and structure refinement

3 Results and discussion

3.1 X-ray crystallography

3.2 Thermal decomposition

3.3 Non-isothermal kinetics analysis

Footnotes

Acknowledgments

References

2.2 Synthesis of NH₄AFT