Synthesis and Characterization of 3,4,5‐Triamino‐1,2,4‐Triazolium 5‐Nitrotetrazolate

3,4,5‐Triamino‐1,2,4‐triazolium 5‐nitrotetrazolate ( 2 ) was synthesized in high yield from 3,4,5‐triamino‐1,2,4‐triazole (guanazine) ( 1 ) and ammonium 5‐nitrotetrazolate. The new compound 2 was characterized by vibrational (IR and Raman) and multinuclear NMR spectroscopy (¹H, ¹³C, ¹⁵N), elemental analysis and single crystal X‐ray diffraction (triclinic, P(‐1), a=0.7194(5), b=0.8215(5), c=0.8668(5) nm, α=75.307(5), β=70.054(5), γ=68.104(5)°, V=0.4421(5) nm³, Z=2, ϱ=1.722 g cm⁻¹, R₁=0.0519 [F>4σ(F)], wR₂(all data)=0.1154). The ¹⁵N NMR spectrum and X‐ray crystal structure (triclinic, P‐1, a=0.5578(5), b=0.6166(5), c=0.7395(5) nm, α=114.485(5)°, β=90.810(5)°, γ=97.846(5)°, V=0.2286(3) nm³, Z=2, ϱ=1.658 g cm⁻¹, R₁=0.0460 [F>4σ(F)], wR₂(all data)=0.1153) of 1 were also determined.     

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.     

Preparation of 1,3‐Diazido‐2‐Nitro‐2‐Azapropane from Urea

An alternative method to prepare 1,3‐diazido‐2‐nitro‐2‐azapropane (DANP), a promising liquid component for high‐energy condensed systems, is suggested and involves the following stages: (i) nitration of urea, (ii) condensation of the nitration product with formaldehyde, (iii) acylation (chlorination) of 1,3‐dihydroxy‐2‐nitro‐2‐azapropane, (iv) chlorination of 1,3‐diacetoxy‐2‐nitro‐2‐azapropane, and (v) azidation of the dichloro derivative to DANP. This synthesis method is selective and enables isolation of 1,3‐diazido‐2‐nitrazapropane devoid of impurities.     

Energetic Salts of 5‐(5‐Azido‐1H‐1,2,4‐triazol‐3‐yl)tetrazole

Several metal and nitrogen‐rich salts of the recently presented 5‐(5‐azido‐1H‐1,2,4‐triazol‐3‐yl)tetrazole (AzTT), including silver ( 1 ), copper(I) ( 2 ), potassium ( 3 ), cesium ( 4 ), copper(II) ( 7 ), ammonium ( 8 ), and guanidinium ( 9 ), as well as the respective double‐salts of 3 , 4 , 8 and 9 , were prepared and well characterized by IR and multinuclear (¹H, ¹³C, ¹⁴N) NMR spectroscopy, DSC, mass spectrometry, elemental analysis and one ( 4 ) additionally by single‐crystal X‐ray diffraction. The sensitivities towards impact, friction and electrostatic discharge were determined according to BAM standards, revealing most of the metal salts as highly sensitive and the nitrogen‐rich salts as insensitive. The metal salts were further tested for their ability of being primary explosives.     

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.     

Seed‐Free Synthesis and Characterization of Zeolite Faujasite Aluminosilicate Coating on α‐Alumina Supports

NaY zeolite was synthesized by a simple sol–gel technique. NaY zeolite membrane was formed on the alumina substrate using optimized solution composition and synthesis conditions. The formation of the NaY zeolite was ascertained by X‐ray powder diffraction, which showed that the crystallinity improved with annealing. The high‐resolution transmission electron microscopy images of samples annealed at 300°C showed the formation of cubic structure corresponding to NaY zeolite. Brunauer–Emmett–Teller analysis revealed that the synthesized zeolite is a well crystallized NaY zeolite. The SEM images revealed the formation of fine structure NaY zeolite membrane on α‐alumina substrate.     

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.     

Synthesis and characterization of nonionic 1‐vinyl‐2‐pyrrolidinone/methacryloxy silicone copolymers: Effects of molecular weight of silicone and crosslinking density

Nonionic 1‐vinyl‐2‐pyrrolidinone/methacryloxy silicone copolymers (VP/VS copolymers) were prepared and characterized as functions of molecular weight of silicone and crosslinking density. Fourier transform infrared spectroscopy, ¹³C‐NMR, and pyrolysis gas chromatography–mass spectrometry study showed that those copolymers were successfully synthesized. Also, the gel‐permeation chromatography spectrum exhibited a fairly narrow distribution of the molecular weight of the polymer. It was found that the turbidity in ethanol (EtOH) and the glass‐transition temperature of crosslinked VP/VS copolymers are influenced by the amount of crosslinking agent. However, in the case of branched VP/VS copolymers, a transparent solution was obtained, regardless of the molecular weight of silicone. SEM/EDS study revealed that silicone is more abundant on the coating surface than on the interface of coating/glass. This is probably because Si‐containing chains have lower surface energy than that of vinylpyrrolidinone‐containing chains. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2244–2253, 2002     

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.     

Synthese und Charakterisierung von O2S2 — und N2S2‐Übergangsmetallkomplexen ausgehend von β‐Chlor) β‐trifluormethylvinylaldehyden

Synthesis and Characterization of O₂S₂ — and N₂S₂‐Transition Metal Complexes Starting from β‐Chloro‐β‐trifluoromethyl Vinylaldehydes The syntheses of complexes 4 and 5 with O₂S₂ ‐and N₂S₂ — donor atom sets are described as one‐step procedures. Their structures were confirmed by NMR, IR, UV‐ VIS and MS spectroscopy. One nickel complex 5a was determined by X‐ray structure analysis whereas the Cu^II complexes were studied by EPR spectroscopy.     

Eu2+‐doped strontium aluminum silicon nitrides having α‐SiAlON and polytypoid structures

Yellow single crystals of aluminum silicon nitrides containing strontium and europium were prepared by heating starting mixtures of Sr₃N₂, Si₃N₄, AlN, and EuN at 2050°C and 0.85 MPa of N₂ for 8 hours. Single‐crystal X‐ray diffraction revealed that prismatic crystals 20‐100 μm in size were Sr_0.31Al_0.62Si_11.38N₁₆:Eu (trigonal, a=7.7937(2) Å, c=5.6519(2) Å, space group P31c), which are isotypic with Sr‐α‐SiAlON, Sr_m/2Al_m+nSi_12?m?nN_16?nO_n, with m=0.62 and n=0. The Eu²⁺ content was approximately 1 at.% of Sr contained in the framework of corner‐sharing (Al/Si)N₄ tetrahedra with an occupancy of 0.154(2). Block‐shaped crystals with a side length of 50‐300 μm were a new polytypoid of Sr‐α‐SiAlON, Sr_2.97Eu_0.03Al₆Si₂₄N₄₀. Streak lines were observed in the direction of the c* axis in the X‐ray oscillation photographs, indicating stacking faults of the structure. The fundamental X‐ray reflections were indexed with a hexagonal cell (a=7.9489(3) Å, c=14.3941(6) Å). The structure was analyzed with a model of space group P in which one of the six Al/Si sites was statistically split into two sites with occupancies of 0.673(5) and 0.227(5). The atomic arrangements in the layers of the structure were similar to those of Sr‐α‐SiAlON, but the stacking sequences of the layers were different. The peak wavelengths and full widths at half maximum of emission spectra measured for the single crystals of Sr_0.31Al_0.62Si_11.38N₁₆:Eu and Sr_2.97Eu_0.03Al₆Si₂₄N₄₀ were 583 nm and 87 nm, and 584 nm and 91 nm, respectively, under 400 nm wavelength light excitation at room temperature.     

Synthesis and Characterization of a New Class of Energetic Compounds – Ammonium Nitriminotetrazolates

1‐Methyl‐5‐nitriminotetrazole ( 1 ) and 2‐methyl‐5‐nitraminotetrazole ( 2 ) obtained by nitration of 1‐methyl‐5‐aminotetrazole ( 3 ) and 2‐methyl‐5‐aminotetrazole ( 4 ) were deprotonated using aqueous ammonia solution yielding the energetic compounds, ammonium 1‐methyl‐5‐nitriminotetrazolate ( 5 ) and ammonium 2‐methyl‐5‐nitriminotetrazolate ( 6 ). The nitrogen‐rich salts were tested and characterized comprehensively using vibrational spectroscopy (Infrared (IR) and Raman), multinuclear (¹H, ¹³C, ¹⁴N, and ¹⁵N) NMR spectroscopy, and elemental analysis. The molecular structures in the crystalline state were determined using low temperature single crystal X‐ray diffraction. The thermal behavior and the decompositions were investigated using differential scanning calorimetry (DSC) and gas IR spectroscopy. The heats of formation were calculated using bomb calorimetric measurements. In addition, the relevant detonation parameters, like the detonation pressure and velocity of detonation were calculated using the software EXPLO5 outperforming the values of TNT. Last but not least the sensitivities were determined using BAM methods showing moderate values against impact and friction (drophammer and friction tester) and the long‐term stabilities were tested using Flexy Thermal safety calorimetry (TSC). X‐ray crystallography: 5 : monoclinic, P2₁/c, a=370.06(2) pm, b=2079.06(9) pm, c=859.69(5) pm, β=99.120(5)°, V=65306(6) pm³, Z=4, ρ_calc=1.639 g cm⁻³; 6 : monoclinic, P2₁, a=365.39(2) pm, b= 788.82(5) pm, c=1124.95(7) pm, β=91.818(6), V=32408(3) pm³, Z=2, ρ_calc=1.651 g cm⁻³.     

The Facile Synthesis and Energetic Properties of an Energetic Furoxan Lacking Traditional “Explosophore” Moieties: (E,E)‐3,4‐bis(oximomethyl)furoxan (DPX1)

Energetic furoxan (E,E)‐3,4‐bis(oximomethyl)furoxan (DPX1) was synthesized in 75 % yield, using a literature procedure, from a precursor readily available in one step from nitromethane. DPX1 was characterized for the first time as an energetic material in terms of calculated performance (V_det = 8245 m s⁻¹; p_C‐J = 29.0 GPa) and measured sensitivity (impact: 10 J; friction: 192 N; T_dec: 168 °C). DPX1 exhibits a sensitivity less than that of RDX, and a performance significantly higher than 2,4,6‐trinitrotoluene (TNT).     

Structural properties of CrF3‐ and MnCl2‐filled poly(vinyl alcohol) films

Poly(vinyl alcohol) (PVA) films filled with different amounts of CrF₃ and MnCl₂ were prepared by the casting method. Differential scanning calorimetry (DSC) and X‐ray diffraction (XRD) analysis were used to study the changes in the structure properties that occurred because of filling. The changes occurring in the measured parameters with increasing filler contents were interpreted in terms of the structural modification of the PVA matrix. All the studied samples had a main melting temperature due to the main crystalline phase of PVA. The intensity and position of this peak depended on the filling level. However, the samples of CrF₃‐filled PVA films with a filling level greater than or equal to 10 wt % revealed another melting temperature, which indicated the presence of a new crystalline phase in addition to the main crystalline phase. The changes that occurred in the degree of crystallinity of the studied samples were examined. The calculated degree of crystallinity was formulated numerically to be an exponential function of the filling level. The XRD patterns of the studied samples confirmed the DSC results. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1115–1120, 2003     

Synthesis and Characterization of the Nitrogen‐Rich Hyperbranched Polymers – Poly([1,2,3]‐Triazole‐[1,3,5]‐Triazine)s

Novel hyperbranched poly([1,2,3]‐triazole‐[1,3,5]‐triazine)s (HBP TT) were synthesized by a 1,3‐dipolar cycloaddition reaction from AB₂ monomer – 2‐azido‐4,6‐bis‐prop‐2‐yn‐1‐yloxy‐ [1,3,5]‐triazine (ABPOT). The monomer contains one azide group A and two terminal alkyne units B. Thermal polymerization of ABPOT in bulk or in DMF solution leads to hyperbranched polymers containing both 1,4‐ and 1,5‐disubstituted [1,2,3]‐triazoles. The monomer was also polymerized catalytically in the presence of Cu(I) salts under mild reaction conditions in DMSO solution and in bulk affording hyperbranched poly‐[1,2,3]‐triazoles 1,4‐disubstituted only. The reactions lead to the products soluble in aprotic polar solvents like DMSO or DMF. Side reactions can proceed in a few cases, particularly: (i) homocoupling of alkyne groups, leading to the formation of insoluble products as a result of cross‐linking, (ii) isomerization of propynyloxytriazine fragments to propynyl‐ or propadienyltriazinone ones, and (iii) hydrolysis of triple bonds without the loss of solubility. Heats of formation of monomer and synthesized polymers were calculated from their combustion heats. All products were characterized by NMR‐, IR‐spectroscopy, and size exclusion chromatography (SEC) data. The obtained results open the prospect for the use of HBP TT as the high‐enthalpy modifiers for energetic and non‐energetic binders.     

Elaboration and thermal analysis of nanocomposites based on poly(methyl methacrylate‐co‐4‐vinylpyridine) and Maghnia bentonite

Nanocomposites based on an organically modified bentonite, from Maghnia Algeria (OBT) and a copolymer of methyl methacrylate with 4‐vinylpyridine (PMM4VP) synthesized in dioxan at room temperature using a neutral Ni(II)α‐benzoinoxime complex as a single component initiator, were elaborated via solution intercalation method and characterized by several techniques. X‐ray diffraction and transmission electron microscopy investigations indicate that mainly exfoliated and intercalated PMM4VP/OBT nanocomposites were elaborated and that the degree of exfoliation decreases with an increase of the OBT loading. Thermal analyses of these nanocomposites compared with their virgin copolymer confirmed a significant improvement of their thermal stability as evidenced by an increase of 28°C in their onset degradation temperatures. In addition, differential scanning calorimetry displayed an increase in the range of 12–18°C in their glass transition temperatures relative to their virgin copolymer. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis of functionalizable derivatives of 3,4‐ethylenedioxythiophene and their solid‐state polymerizations

Four polythiophenes based on poly(3,4‐ethylenedioxythiophene) (PEDOT) framework have been successfully prepared by the facile thermal activated solid‐state polymerization (SSP) process from their corresponding dibromothiophene derivatives, which were efficiently obtained using our improved methodology. Rates of polymerizations of these precursors were varied and most of the processes were incomplete under the reaction condition chosen for the synthesis. Raising the reaction temperature of the SSP further advanced the polymerization progress and improved the conductive properties of the polymer. The polymer of 3,4‐ethylenedioxythiophene‐methanol (EDTM) and its two related derivatives with functionalizable groups were prepared for the first time by the SSP method. The process and these new SSP‐derived polymers could help solving the fabrication difficulty and expand the scope of their applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42233.     

Synthesis and Energetic Properties of 4,4′,5,5′‐Tetranitro‐2,2′‐biimidazolate(N4BIM) Salts

This paper describes the synthesis and characterization of several salts of 4,4′,5,5′‐tetranitro‐2,2′‐biimidazolate (N4BIM). Each of the salts were characterized chemically, thermally, morphologically, as well as with respect to destructive stimuli (impact, electrostatic discharge, friction, thermal). These salts show promise as propellant ingredient additives, and in particular, the bis‐triaminoguanidinium salt of N4BIM displays excellent burn rate and combustion behavior. Our combustion studies have shown that TAGN4BIM displays a fast burning rate and has the lowest pressure dependence exponent yet measured for a triaminoguanidinium salt.     

Synthesis and properties of novel organosoluble bismaleimides and polyaspartimides containing bis(4‐maleimido‐3, 5‐dimethyl phenyl) halo phenyl methane

A series of bismaleimides was synthesized from bis(4‐amino‐3, 5‐dimethylphenyl) (X) phenyl methane (X = 3′chloro, 3′‐bromo, 3′‐benzyloxy, 4′‐chloro, 4′‐fluoro) and maleic anhydride. The bismaleimides were subsequently polymerized with various diamines by Michael addition to yield novel polyaspartimides. All the polymers exhibited good solubility in organic solvents and the inherent viscosity of the polymers were in the range of 0.40–0.56 dL/g, which is good enough to fabricate composites and films. The temperature at which 10% weight loss occurred was in the range of 390–441°C. The polymers had high glass transition temperature in the range of 205–275°C and left about 31.95–84.20% char yield at 800°C indicating that they have good self‐extinguishing property. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and Energetic Properties of Bis‐(Triaminoguanidinium) 3,3′‐Dinitro‐5,5′‐Azo‐1,2,4‐Triazolate (TAGDNAT): A New High‐Nitrogen Material

This paper describes the synthesis and characterization of bis‐(triaminoguanidinium)‐3,3′‐dinitro‐5,5′‐azo‐1,2,4‐triazolate (TAGDNAT), a novel high‐nitrogen molecule that derives its energy release from both a high heat of formation and intramolecular oxidation reactions. TAGDNAT shows promise as a propellant or explosive ingredient not only due to its high nitrogen content (66.35 wt.‐%) but also due to its high hydrogen content (4.34 wt.‐%). This new molecule has been characterized with respect to its morphology, sensitivity properties, explosive, and combustion performance. The heat of formation of TAGDNAT was also experimentally determined. The results of these studies show that TAGDNAT has one of the fastest low‐pressure burning rates (at 6.9 MPa) measured till date, 6.79 cm s⁻¹ at 6.9 MPa (39% faster than triaminoguanidinium azotetrazolate (TAGzT), a comparable high‐nitrogen/high‐hydrogen material). Furthermore, its pressure sensitivity is 0.507, a 33% reduction compared to TAGzT.