Preparation, characterization of spherical 1,1-diamino-2,2-dinitroethene (FOX-7), and study of its thermal decomposition characteristics

Zhao, Xinhua; He, Dan; Ma, Xiaoping; Liu, Xueying; Xu, Zhen-Lin; Chen, Lizhen; Wang, Jianlong

doi:10.1039/d1ra05836c

Cited by 11 publications

(6 citation statements)

References 24 publications

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“…FT-IR spectroscopy was adopted to further characterize the PYX structure. As shown in Figure 5, the FT-IR spectra of RPYX and CPYX show the same absorption bands of -NO2 and -NH2 functional groups in the wavenumber ranges of 1423-1635 cm −1 and 3259-3442 cm −1 , respectively, with numerous peaks in the fingerprint region [20,21], suggesting that no polymorphic changes occurred during the crystallization process.…”

Section: Structurementioning

confidence: 80%

Effect of Cubic Crystal Morphology on Thermal Characteristics and Mechanical Sensitivity of PYX

Luo,

Wang,

Liu

et al. 2024

Crystals

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To investigate the influence of the cubic crystal morphology on the thermal properties and sensitivity of 2,6-bis(picrylamino)-3,5-dinitropyridine (PYX), cubic PYX (CPYX) crystals were prepared using the antisolvent method. Scanning electron microscopy (SEM), laser particle size analysis, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the morphology, particle size and structure of the prepared products. The thermal behavior, thermal decomposition kinetics, thermal safety parameters and thermal decomposition mechanism of CPYX were investigated by differential scanning calorimetry–thermogravimetry–mass spectrometry–Fourier transform infrared spectrometry (DSC-TG-MS-FT-IR) and in situ FT-IR experiments. Meanwhile, the mechanical sensitivity of CPYX was determined by means of the explosion probability method. The results showed that the product had a smooth cubic morphology and small crystal aspect ratio with an average particle size (d50) of 10.65 μm, but it had no distinct differences from the crystal structure of raw PYX (RPYX). The thermal decomposition peak temperature, the self-accelerating decomposition temperature and the critical temperature of the thermal explosion of CPYX increased by 7.2 °C, 6.1 °C and 10.4 °C, respectively, compared to RPYX. Similarly, the apparent activation energy increased by 15%. Besides these, the impact sensitivity and friction sensitivity of CPYX decreased by 36% and 20%, respectively, compared to RPYX. The decomposition process of CPYX contains two stages. The first stage involves the breakage of N-H bonds and -NO2 groups with the release of CO2, N2O, NO, HCN and H2O, followed by the thermal decomposition of the resulting intermediate and the release of CO2, N2O and HCN in the second stage.

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Section: Structurementioning

confidence: 80%

Effect of Cubic Crystal Morphology on Thermal Characteristics and Mechanical Sensitivity of PYX

Luo,

Wang,

Liu

et al. 2024

Crystals

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“…However, numerous energetic materials with excellent energy performance are limited by high sensitivity. Commercial explosives such as TATB and 1,1-diamino-2,2-dinitroethene (FOX-7) have already confirmed the benefits of HB systems and π–π interactions in terms of improving stability. , In the crystal of FNPI-1 , the strong HB systems are produced by substituted groups with water molecules, and the interlayer intermolecular interactions are also shown in the π-conjugated fused rings. The impart (IS) and friction sensitivities (FS) were measured by standard BAM drop hummer and friction tester techniques .…”

Section: Resultsmentioning

confidence: 99%

Highly Selective Nitroamino Isomerization Guided by Proton Transport Dynamics: Full-Nitroamino Imidazole[4,5-d]pyridazine Fused-Ring System

Wang

Staples

et al. 2022

ACS Appl. Mater. Interfaces

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Due to the advantage of the hydrogen bond system formed by nitroamino isomerization, by the calculations of hydrogen transfer in reported nitroamino explosives, the proton transport dynamics was first proposed to predict the nitroamino isomerization of energetic materials. With the calculated results of zero-point energy, the full-nitroamino fused energetic materials, 2,4-nitroamino-7-nitroimino-1,5-dihydro-4H-imidazolo [4,5-d]pyridazine (FNPI-1) and 2,2′,7,7′-tetranitromino-4,4′-azo-imidazolo[4,5-d]pyridazine (FNPI-2) were designed and successfully synthesized. The highly selective nitroamino isomerization of neutral compound FNPI-1 is shown by Xray diffraction. After the hydrogen transfer occurs, the intermolecular hydrogen bonds will greatly promote tight stacking, which enhances the density and thus a series of comprehensive properties of energetic materials. The theoretical calculations of zero-point energy explain perfectly the selectivity of hydrogen transfer between the nitroamino groups and the fused-ring skeleton for FNPI-1. The hydrogen atom transfer and selective isomerization of nitroamino energetic materials can be accurately predicted following proton transport dynamics, which provides computational bases and new ideas for the efficient design of fully nitroamino-based explosives.

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“…In this regard, 1,1diamino-2,2-dinitroethylene, commonly known as FOX-7 or DADNE, is a promising candidate that has attracted considerable attention over the past decades. This molecule was first synthesized by O ¨stmark and Bemm in 1998 and features easy synthesis procedures, [1][2][3][4] low sensitivity to heat, [5][6][7][8][9][10] and high detonation performance. 11,12 Thus, it has been considered an alternative to well-known explosives, such as 1,3,5-trinitro-2-oxo-1,3,5-triazacyclo-hexane (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclo-octane (HMX).…”

Section: Introductionmentioning

confidence: 99%

“…18 Numerous experimental studies have been attempted to establish the interplay between the chemical structure and properties of FOX-7. 4,13,[18][19][20][21][22][23] Jones and co-workers studied the thermal decomposition of FOX-7 in different phases with simultaneous thermogravimetrydifferential thermal analysis-Fourier transform infrared spectroscopy-mass spectrometry (TG-DTA-FTIR-MS) measurements and differential scanning calorimetry. They observed a two-step decomposition process: the first step yields water (H 2 O), carbon dioxide (CO 2 ), dinitrogen oxide (N 2 O), hydrogen cyanide (HCN), nitrogen dioxide (NO 2 ), and isocyanic acid (HOCN), and the second step forms nitrous acid (HONO) and formic acid (HCOOH).…”

Section: Introductionmentioning

confidence: 99%

Initial decomposition pathways of 1,1-diamino-2,2-dinitroethylene (α-FOX-7) in the condensed phase

Yadav,

Luo,

Kaiser

et al. 2024

Phys. Chem. Chem. Phys.

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Preparation, characterization of spherical 1,1-diamino-2,2-dinitroethene (FOX-7), and study of its thermal decomposition characteristics

Abstract: Spherical FOX-7 was produced via a combination of cooling crystallization method and repeated grinding technique, and the crystal morphology, size, structure, and thermal behavior were systematically investigated in detail.

Cited by 11 publications

References 24 publications

Effect of Cubic Crystal Morphology on Thermal Characteristics and Mechanical Sensitivity of PYX

Effect of Cubic Crystal Morphology on Thermal Characteristics and Mechanical Sensitivity of PYX

Highly Selective Nitroamino Isomerization Guided by Proton Transport Dynamics: Full-Nitroamino Imidazole[4,5-d]pyridazine Fused-Ring System

Initial decomposition pathways of 1,1-diamino-2,2-dinitroethylene (α-FOX-7) in the condensed phase

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