Computed Thermodynamic and Explosive Properties of 1‐Azido‐2‐nitro‐2‐azapropane (ANAP)

Some thermodynamic and explosive properties of the recently reported 1‐azido‐2‐nitro‐2‐azapropane (ANAP) have been determined in a combined computational ab initio (MP2/aug‐cc‐pVDZ) and EXPLO5 (Becker–Kistiakowsky–Wilson's equation of state, BKW EOS) study. The enthalpy of formation of ANAP in the liquid phase was calculated to be Δ_fH°, ANAP(l)=+297.1 kJ mol⁻¹. The heat of detonation (Q_v), the detonation pressure (P), and the detonation velocity of ANAP were calculated to be Q_v=−6088 kJ kg⁻¹, P=23.8 GPa, D=8033 m s⁻¹. A mixture of ANAP and tetranitromethane (TNM) was investigated in an attempt to tailor the impact sensitivity of ANAP, but results obtained indicate that the mixture is almost as sensitive as pure ANAP. On the other hand, ANAP and TNM were found to be chemically compatible (¹H, ¹³C, ¹⁴N NMR; DSC) and a 1 : 1 mixture (by weight) of both components was calculated to have superior explosive properties than either of the individual components: Q_v=−6848 kJ kg⁻¹, P=27.0 GPa, D=8284 m s⁻¹.     

A DFT Study on the Structures and Energies of Isomers of 4‐Amino‐1,3‐dinitro‐1,2,4‐triazol‐5‐one‐2‐oxide: New High Energy Density Compounds

Isomers of 4‐amino‐1,3‐dinitrotriazol‐5‐one‐2‐oxide (ADNTONO) are of interest in the contest of insensitive explosives and were found to have true local energy minima at the DFT‐B3LYP/aug‐cc‐pVDZ level. The optimized structures, vibrational frequencies and thermodynamic values for triazol‐5‐one N‐oxides were obtained in their ground state. Kamlet‐Jacob equations were used to evaluate the performance properties. The detonation properties of ADNTONO (D=10.15 to 10.46 km s⁻¹, P=50.86 to 54.25 GPa) are higher compared with those of 1,1‐diamino‐2,2‐dinitroethylene (D=8.87 km s⁻¹, P=32.75 GPa), 5‐nitro‐1,2,4‐triazol‐3‐one (D=8.56 km s⁻¹, P=31.12 GPa), 1,2,4,5‐tetrazine‐3,6‐diamine‐1,4‐dioxide (D=8.78 km s⁻¹, P=31.0 GPa), 1‐amino‐3,4,5‐trinitropyrazole (D=9.31 km s⁻¹, P=40.13 GPa), 4,4′‐dinitro‐3,3′‐bifurazan (D=8.80 km s⁻¹, P=35.60 GPa) and 3,4‐bis(3‐nitrofurazan‐4‐yl)furoxan (D=9.25 km s⁻¹, P=39.54 GPa). The  NH₂ group(s) appears to be particularly promising area for investigation since it may lead to two desirable consequences of higher stability (insensitivity), higher density, and thus detonation velocity and pressure.     

Characterization of 4,6‐Diazido‐N‐nitro‐1,3,5‐triazine‐2‐amine

4,6‐Diazido‐N‐nitro‐1,3,5‐triazine‐2‐amine (DANT) was prepared with a 35 % yield from cyanuric chloride in a three step process. DANT was characterized by IR and NMR spectroscopy (¹H, ¹³C, ¹⁵N), single‐crystal X‐ray diffraction, and DTA. The crystal density of DANT is 1.849 g cm⁻³. The cyclization of one azido group and one nitrogen atom of the triazine group giving tetrazole was observed for DANT in a dimethyl sulfoxide solution using NMR spectroscopy. An equilibrium exists between the original DANT molecule and its cyclic form at a ratio of 7 : 3. The sensitivity of DANT to impact is between that for PETN and RDX, sensitivity to friction is between that for lead azide and PETN, and sensitivity to electric discharge is about the same as for PETN. DANT′s heat of combustion is 2060 kJ mol⁻¹.     

Structural and Thermal Characterization of A Novel High Nitrogen Energetic Material: (NH4)2DNMT

1,4‐Dihydro‐5H‐(dinitromethylene)‐tetrazole ammonium salt ((NH₄)₂DNMT), a high nitrogen energetic compound, was synthesized and structurally characterized by single‐crystal X‐ray diffraction. The thermal behavior of (NH₄)₂DNMT was studied with DSC and TG‐DTG methods. The kinetic equation of the thermal decomposition reaction is: dα/dT=10^13.17/3β(1−α)⁻² exp(−1.388×10⁵/RT). The critical temperature of thermal explosion is 182.7 °C. The specific heat capacity of (NH₄)₂DNMT was determined and the molar heat capacity is 301 J mol⁻¹ K⁻¹ at 298.15 K. The adiabatic time‐to‐explosion of (NH₄)₂DNMT was calculated to be 277 s. The detonation velocity and detonation pressure were also estimated. All results showed that (NH₄)₂DNMT presents good performance.     

Improved Synthesis and X‐Ray Structure of 5‐Aminotetrazolium Nitrate

5‐Aminotetrazolium nitrate was synthesized in high yield and characterized using Raman and multinuclear NMR spectroscopy (¹H, ¹³C, ¹⁵N). The molecular structure of 5‐aminotetrazolium nitrate in the crystalline state was determined by X‐ray crystallography: monoclinic, P 2₁/c, a=1.05493(8) nm, b=0.34556(4) nm, c=1.4606(1) nm, β=90.548(9)°, V=0.53244(8) nm³, Z=4, ϱ=1.847 g cm⁻³, R₁=0.034, wR₂ (all data)=0.090. The thermal stability of 5‐aminotetrazolium nitrate was determined using differential scanning calorimetry; the compound decomposes at 167 °C. The enthalpy of combustion (Δ_combH) of 5‐aminotetrazolium nitrate ([CH₄N₅]⁺[NO₃]⁻) was determined experimentally using oxygen bomb calorimetry: Δ_combH([CH₄N₅]⁺[NO₃]⁻)=−6020±200 kJ kg⁻¹. The standard enthalpy of formation (Δ_fH°) of [CH₄N₅]⁺[NO₃]⁻ was obtained on the basis of quantum chemical computations at the electron‐correlated ab initio MP2 (second order Møller‐Plesset perturbation theory) level of theory using a correlation consistent double‐zeta basis set (cc‐pVTZ): Δ_fH°([CH₄N₅]⁺[NO₃]⁻(s))=+87 kJ mol⁻¹=+586 kJ kg⁻¹. The detonation velocity (D) and the detonation pressure (P) of 5‐aminotetrazolium nitrate were calculated using the empirical equations by Kamlet and Jacobs: D([CH₄N₅]⁺[NO₃]⁻)=8.90 mm μs⁻¹ and P([CH₄N₅]⁺[NO₃]⁻)=35.7 GPa.     

Chemical Transformation of Octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) Induced by Low Energy Electron Beam Irradiation

The effects of 8.0×10⁻¹⁷ J (500 eV) and 3.2×10⁻¹⁹ J (2 eV) electrons on chemical structure of octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) were studied in situ, under ultra‐high vacuum conditions using a combination of X‐ray photoelectron spectroscopy (XPS) and quadrupole mass spectrometry. XPS data indicated that electrons impact by 8.0×10⁻¹⁷ J for 30 s caused a decrease in nitro group concentration, and a little shift in the binding energy of the nitrogen 1s peak. Such a phenomenon was found at very low kinetic energy (3.2×10⁻¹⁹ J) with time evolution. Quadrupole mass spectrometry detected gas desorption after electron irradiation included H₂O and H₂ mostly. Microscopy‐IR spectroscopic investigations also proved that the intensity of nitro groups of HMX after irradiation decreased compared with those of the pristine HMX. We attributed the structure changes obtained by XPS and IR spectroscopy result in a chemical transformation, which was associated with low‐energy dissociative electron attachment (DEA) of surface contaminants followed by deoxidization reactions to form the product molecules.     

Synthesis and Characterization of 1,4‐Dimethyl‐5‐Aminotetrazolium 5‐Nitrotetrazolate

1,4‐Dimethyl‐5‐aminotetrazolium 5‐nitrotetrazolate ( 2 ) was synthesized in high yield from 1,4‐dimethyl‐5‐aminotetrazolium iodide ( 1 ) and silver 5‐nitrotetrazolate. Both new compounds ( 1, 2 ) were characterized using vibrational (IR and Raman) and multinuclear NMR spectroscopy (¹H, ¹³C, ¹⁴N, ¹⁵N), elemental analysis and single crystal X‐ray diffraction. 1,4‐Dimethyl‐5‐aminotetrazolium 5‐nitrotetrazolate ( 2 ) represents the first example of an energetic material which contains both a tetrazole based cation and anion. Compound 2 is hydrolytically stable with a high melting point of 190 °C (decomposition). The impact sensitivity of compound 2 is very low (30 J), it is not sensitive towards friction (>360 N). The molecular structure of 1,4‐dimethyl‐5‐aminotetrazolium iodide ( 1 ) in the crystalline state was determined by X‐ray crystallography: orthorhombic, F_ddd, a=1.3718(1) nm, b=1.4486(1) nm, c=1.6281(1) nm, V=3.2354(5) nm³, Z=16, ρ=1.979 g cm⁻¹, R₁=0.0169 (F>4σ(F)), wR₂ (all data)=0.0352.     

Synthesis,Crystal Structure,and Thermal Behaviors of 3‐Nitro‐1,5‐bis(4,4′‐dimethylazide)‐1,2,3‐triazolyl‐3‐azapentane (NDTAP)

The energetic material, 3‐nitro‐1,5‐bis(4,4′‐dimethyl azide)‐1,2,3‐triazolyl‐3‐azapentane (NDTAP), was firstly synthesized by means of Click Chemistry using 1,5‐diazido‐3‐nitrazapentane as main material. The structure of NDTAP was confirmed by IR, ¹H NMR, and ¹³C NMR spectroscopy; mass spectrometry, and elemental analysis. The crystal structure of NDTAP was determined by X‐ray diffraction. It belongs to monoclinic system, space group C2/c with crystal parameters a=1.7285(8) nm, b=0.6061(3) nm, c=1.6712(8) nm, β=104.846(8)°, V=1.6924(13) nm³, Z=8, μ=0.109 mm⁻¹, F(000)=752, and D_c=1.422 g cm⁻³. The thermal behavior and non‐isothermal decomposition kinetics of NDTAP were studied with DSC and TG‐DTG methods. The self‐accelerating decomposition temperature and critical temperature of thermal explosion are 195.5 and 208.2 °C, respectively. NDTAP presents good thermal stability and is insensitive.     

Ethylene/1‐octadecene copolymerization using [η5:η1‐C5Me4‐4‐R1‐6‐R‐C6H2O]TiCl2 catalysts

Copolymerization of ethylene with 1‐octadecene was studied using [η⁵:η¹‐C₅Me₄‐4‐R₁‐6‐R‐C₆H₂O]TiCl₂ [R₁ = ^tBu (1), H (2, 3, 4); R = ^tBu (1, 2), Me (3), Ph (4)] as catalysts in the presence of Al(i‐Bu)₃ and [Ph₃C][B(C₆F₅)₄]. The effect of the concentration of comonomer in the feed and Al/Ti molar ratio on the catalytic activity and molecular weight of the resultant copolymer were investigated. The substituents on the phenyl ring of the ligand affect considerably both the catalytic activity and comonomer incorporation. The 1 /Al(i‐Bu)₃/[Ph₃C][B(C₆F₅)₄] catalyst system exhibits the highest catalytic activity and produces copolymers with the highest molecular weight, while the 2 /Al(i‐Bu)₃/[Ph₃C][B(C₆F₅)₄] catalyst system gives copolymers with the highest comonomer incorporation under similar conditions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Structural and Preliminary Explosive Property Characterizations of New 3,4,5‐Triamino‐1,2,4‐triazolium (Guanazinium) Salts

Two new highly stable energetic salts were synthesized in reasonable yield by using the high nitrogen‐content heterocycle 3,4,5‐triamino‐1,2,4‐triazole and resulting in its picrate and azotetrazolate salts. 3,4,5‐Triamino‐1,2,4‐triazolium picrate (1) and bis(3,4,5‐triamino‐1,2,4‐triazolium) 5,5′‐azotetrazolate (2) were characterized analytically and spectroscopically. X‐ray diffraction studies revealed that protonation takes place on the nitrogen N1 (crystallographically labelled as N2). The sensitivity of the compounds to shock and friction was also determined by standard BAM tests revealing a low sensitivity for both. B3LYP/6–31G(d, p) density functional (DFT) calculations were carried out to determine the enthalpy of combustion (Δ_cH (1) =−3737.8 kJ mol⁻¹, Δ_cH (2) =−4577.8 kJ mol⁻¹) and the standard enthalpy of formation (Δ_fH° (1) =−498.3 kJ mol⁻¹, (Δ_fH° (2) =+524.2 kJ mol⁻¹). The detonation pressures (P (1) =189×10⁸ Pa, P (2) =199×10⁸ Pa) and detonation velocities (D (1) =7015 m s⁻¹, D (2) =7683 m s⁻¹) were calculated using the program EXPLO5.     

Electrochemical Performance of MnO2‐based Air Cathodes for Zinc‐air Batteries

This paper compares the oxygen reduction on four MnO₂‐based air cathodes assembled in home‐made electrochemical cells, with some particular observations on α‐MnO₂ cathode. The results show that the catalytic activity decreases in the following order: electrolytic MnO₂ (EMD) > natural MnO₂ (NMD) > β‐MnO₂ > α‐MnO₂. The maximum power density of the zinc‐air battery with EMD as the catalyst reaches up to 141.8 mW cm⁻² at the current density of 222.5 mA cm⁻², which is about 60%, 20% and 10% higher than that of α‐MnO₂ (90.0 mW cm⁻² at 120.3 mA cm⁻²), β‐MnO₂ (121.5 mW cm⁻² at 150.4 mA cm⁻²) and NMD (128.2 mW cm⁻² at 207.8 mA cm⁻²), respectively. It is believed that its unique crystal structure and biggest BET surface area make EMD have the smallest charge transfer resistance (R_ct), thus EMD has the highest activity.     

Water‐sorption and metal‐uptake behavior of pH‐responsive poly (N‐acryloyl‐N′‐methylpiperazine) gels

Hydrogels based on N‐acryloyl‐N′‐methylpiperazine (AcrNMP) swelled extensively in solutions of low pH due to the protonation of the tertiary amine. The water transport in the gels under an acidic condition was non‐Fickian and nearly Fickian in neutral pH with the collective diffusion coefficients determined as 2.08 × 10⁻⁷ and 5.00 × 10⁻⁷ cm⁻² s⁻¹, respectively. These gels demonstrated good metal‐uptake behavior with various divalent metal ions, in particular, copper and nickel, with the uptake capacity increased with increasing pH. The swelling ratio of the gel in the presence of metal ions decreased with increasing metal ion uptake. The results suggest that high metal ion uptake can lead to physical crosslinking arising from the interchain metal complex formation. The metal‐loaded gels could be stripped easily with 1M H₂SO₄ without any loss in their uptake capacity. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 268–273, 2001     

Non‐Isothermal Kinetic Study of the Thermal Decomposition of Melamine 3‐Nitro‐1,2,4‐triazol‐5‐one Salt

Study on thermal behavior of 3‐nitro‐1,2,4‐triazol‐5‐one (NTO) salts was required to obtain important data for application purposes. These compounds have been shown to be useful intermediates for gun propellant ingredients, high energetic ballistic modifiers for solid propellants and other potential applications. In this paper, thermal decomposition and non‐isothermal kinetics of melamine 3‐nitro‐1,2,4‐triazol‐5‐one salt (MNTO) were studied under non‐isothermal conditions by DSC and TG methods. The kinetic parameters were obtained from analysis of the DSC and TG curves by Kissinger and Ozawa methods. The critical temperature of thermal explosion (T_b) was 574 K. The results show that MNTO is thermally more stable than NTO when compared in terms of the critical temperature of thermal explosion. Finally, the values of ΔS^#, ΔH^#, and ΔG^# of its decomposition reaction were calculated.     

Crystal Structure and Improved Synthesis of 1‐(2H‐Tetrazol‐5‐yl)guanidium Nitrate

Energetic derivatives of tetrazoles are one of the key areas of research focus in pursuit of novel high energy materials, useful as propellants and explosives. Herein, the crystal structure and an improved synthetic procedure of 1‐(2H‐tetrazol‐5‐yl)guanidine ( 1 ) and its nitrate salt ( 2 ) are reported. The compounds were structurally characterized by spectroscopic (FT‐IR, ¹H NMR, ¹³C NMR) and elemental analysis. The molecular structure of tetrazolyl guanidium nitrate ( 2 ) was solved using low temperature single‐crystal X‐ray diffraction. 2 crystallized as its hemihydrate in the orthorhombic space group Fdd2, with a crystal density of 1.69 g cm⁻³. Thermal behavior and decomposition of the molecules were studied with differential scanning calorimetry (DSC). Molar enthalpy of formation (Δ_fH^m) of compound 2 was back calculated from heat of combustion (Δ_cH⁰) value obtained experimentally using bomb calorimetric measurements. Lattice enthalpy of 1‐(2H‐tetrazol‐5‐yl)guanidium nitrate was directly calculated from measured crystal density using Jenkins equation. Preliminary ballistic parameters of the compound were predicted and compared with reported high nitrogen tetrazole derivatives.     

Rational Design,Synthesis, and Potency of N‐Substituted Indoles,Pyrroles, and Triarylpyrazoles as Potential Fructose 1,6‐Bisphosphatase Inhibitors

By using computer modeling and lead structures from our earlier SAR results, a broad variety of pyrrole‐, indole‐, and pyrazole‐based compounds were evaluated as potential fructose 1,6‐bisphosphatase (FBPase) inhibitors. The docking studies yielded promising structures, and several were selected for synthesis and FBPase inhibition assays: 1‐[4‐(trifluoromethyl)benzoyl]‐1H‐indole‐5‐carboxamide, 1‐(α‐naphthalen‐1‐ylsulfonyl)‐7‐nitro‐1H‐indole, 5‐(4‐carboxyphenyl)‐3‐phenyl‐1‐[3‐(trifluoromethyl)phenyl]‐1H‐pyrazole, 1‐(4‐carboxyphenylsulfonyl)‐1H‐pyrrole, and 1‐(4‐carbomethoxyphenylsulfonyl)‐1H‐pyrrole were synthesized and tested for inhibition of FBPase. The IC₅₀ values were determined to be 0.991 and 1.34 μM , and 575, 135, and 32 nM , respectively. The tested compounds were significantly more potent than the natural inhibitor AMP (4.0 μM ) by an order of magnitude; indeed, the best inhibitor showed an IC₅₀ value toward FBPase more than two orders of magnitude better than that of AMP. This level of activity is virtually the same as that of the best currently known FBPase inhibitors. This work shows that such indole derivatives are promising candidates for drug development in the treatment of type II diabetes.     

Synthesis,extraction, and anti‐bacterial studies of some new bis‐1,2,4‐triazole derivatives part I

A series of new bis triazole Schiff base derivatives (4) were prepared in good yields by treatment of 4‐amino‐3,5‐diphenyl‐4H‐1,2,4‐triazole (3) with bisaldehydes (1). Schiff bases (4) were reduced with NaBH₄ to afford the corresponding bisaminotriazoles (5). All the new compounds were characterized by IR, ¹H NMR and ¹³C NMR spectral data. Their overall extraction (log K_ex) constants for 1 : 1 (M : L) complexes and CHCl₃/H₂O systems were determined at 25 ± 0.1°C to investigate the relationship between structure and selectivity toward various metal cations. The extraction equilibrium constants were estimated using CHCl₃/H₂O membrane transfer with inductively coupled plasma‐atomic emission spectroscopy spectroscopy. The stability sequence of the triazole derivatives in CHCl₃ for the metal cations was exhibited a characteristic preference order of extractability to metal ions [Fe(III) > Cu(II) > Pb(II) > Co(II) > Ni(II) > Mn(II) > Zn(II) > Mg(II) > Ca(II)]. The compounds were tested for anti‐microbial activity applying agar diffusion technique for 11 bacteria. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Gold‐cyanide biosorption with L‐cysteine

L ‐Cysteine increased gold‐cyanide biosorption by protonated Bacillus subtilis, Penicillium chrysogenum and Sargassum fluitans biomass. At pH 2, the maximum Au uptakes were 20.5 µmol g⁻¹, 14.2 µmol g⁻¹ and 4.7 µmol g⁻¹ of Au, respectively, approximately 148–250% of the biosorption performance in the absence of cysteine. Au biosorption mainly involved anionic AuCN₂⁻ species adsorbed by ionizable functional groups on cysteine‐loaded biomass carrying a positive charge when protonated [(biomass–cysteine–H⁺)–(AuCN₂⁻)]. Deposited gold could be eluted from Au‐loaded biomass at pH 3–5. The elution efficiencies were higher than 92% at pH 5.0 with the Solid‐to‐Liquid ratio, S/L, = 4. Increasing solution ionic strength (NaNO)₃ decreased Au uptake. FTIR analyses indicated that the main functional groups involved in gold biosorption in the presence of L ‐cysteine are probably N‐, S‐ and O‐containing groups. The present results confirm that certain waste microbial biomaterials are capable of effectively removing and concentrating gold from solutions containing residual cyanide if applied under appropriate conditions. © 2000 Society of Chemical Industry     

Organosoluble and light‐colored fluorinated polyimides based on 1,1‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]‐1‐phenylethane and various aromatic dianhydrides

To investigate the CF₃ group affecting the coloration and solubility of polyimides (PI), a novel fluorinated diamine 1,1‐bis[4‐(4‐amino‐2‐ trifluoromethylphenoxy)phenyl]‐1‐phenylethane (2) was prepared from 1,1‐ bis(4‐hydrophenyl)‐1‐phenylethan and 2‐chloro‐5‐nitrobenzotrifluoride. A series of light‐colored and soluble PI 5 were synthesized from 2 and various aromatic dianhydrides 3a–f using a standard two‐stage process with thermal 5a– f(H) and chemical 5a–f(C) imidization of poly(amic acid). The 5 series had inherent viscosities ranging from 0.55 to 0.98 dL/g. Most of 5a–f(H) were soluble in amide‐type solvents, such as N‐methyl‐2‐pyrrolidone (NMP), N,N‐ dimethylacetamide (DMAc), and N,N‐dimethylformamide (DMF), and even soluble in less polar solvents, such as m‐Cresol, Py, Dioxane, THF, and CH₂Cl₂, and the 5(C) series was soluble in all solvents. The GPC data of the 5a–f(C) indicated that the Mn and Mw values were in the range of 5.5–8.7 × 10⁴ and 8.5–10.6 × 10⁴, respectively, and the polydispersity index (PDI) Mw /Mn values were 1.2–1.5. The PI 5 series had excellent mechanical properties. The glass transition temperatures of the 5 series were in the range of 232–276°C, and the 10% weight loss temperatures were at 505–548 °C in nitrogen and 508–532 °C in air, respectively. They left more than 56% char yield at 800°C in nitrogen. These films had cutoff wavelengths between 356.5–411.5 nm, the b* values ranged from 5.0–71.1, the dielectric constants, were 3.11–3.43 (1MHz) and the moisture absorptions were in the range of 011–0.40%. Comparing 5 containing the analogous PI 6 series based on 1,1‐bis[4‐(4‐aminophenoxy)phenyl]‐1‐ phenylethane (BAPPE), the 5 series with the CF₃ group showed lower color intensity, dielectric constants, and better solubility. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2399–2412, 2005     

Electrochemical Analysis of a System Based on W and Ni Combined with CeO2 as Potential Sulfur‐tolerant SOFC Anode

A formulation of tungsten and nickel combined with CeO₂ (WNi‐Ce) was prepared and evaluated as sulfur‐tolerant anode for SOFC at intermediate temperature. Structural and morphological changes that take place in the system upon interactions with hydrogen sulfide were analyzed. The electrochemical performance was tested in a single cell, WNi‐Ce/LDC/LSGM/LSFC, varying H₂S concentration (0–500 ppm) at 750 °C using I–V curves, impedance spectroscopy and load demands. The highest cell performance was reached in H₂ and decrease with H₂S content increase in the fuel from 226 mW cm⁻² in pure H₂ to 108 mW cm⁻² in 500 ppm H₂S/H₂. Essentially, no decay in the cell performance was observed in the several short‐term load tests studied under several H₂S concentration (0–500 ppm) during 1h, and even in 500 ppm H₂S/H₂ during 70 h, indicating that this material could be a potential sulfur‐tolerant anode.     

Synthesis,Crystal Structure,and Thermal Behavior of 3‐(4‐Aminofurazan‐3‐yl)‐4‐(4‐nitrofurazan‐3‐yl)furazan (ANTF)

The energetic material 3‐(4‐aminofurazan‐3‐yl)‐4‐(4‐nitrofurazan‐3‐yl)furazan (ANTF) with low melting‐point was synthesized by means of an improved oxidation reaction from 3,4‐bis(4′‐aminofurazano‐3′‐yl)furazan. The structure of ANTF was confirmed by ¹³C NMR spectroscopy, mass spectrometry, and the crystal structure was determined by X‐ray diffraction. ANTF crystallized in monoclinic system P2₁/c, with a crystal density of 1.785 g cm⁻³ and crystal parameters a=6.6226(9) Å, b=26.294(2) Å, c=6.5394(8) Å, β=119.545(17)°, V=0.9907(2) nm³, Z=4, μ=0.157 mm⁻¹, F(000)=536. The thermal stability and non‐isothermal kinetics of ANTF were studied by differential scanning calorimetry (DSC) with heating rates of 2.5, 5, 10, and 20 K min⁻¹. The apparent activation energy (E_a) of ANTF calculated by Kissinger's equation and Ozawa's equation were 115.9 kJ mol⁻¹ and 112.6 kJ mol⁻¹, respectively, with the pre‐exponential factor lnA=21.7 s⁻¹. ANTF is a potential candidate for the melt‐cast explosive with good thermal stability and detonation performance.