Decomposition Mechanism of Hexanitrohexaazaisowurtzitane (CL-20) by Coupled Computational and Experimental Study

Kumar, Macharla Arun; Ashutosh, Parimi; Vargeese, Anuj A.

doi:10.1021/acs.jpca.9b01197

Cited by 30 publications

(20 citation statements)

References 22 publications

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“…The temperature is about 240 °C. There are certainly N 2 O (1274 cm –1 ), NO 2 (1644 and 1596 cm –1 ), HCN (737 cm –1 ), CO 2 (670 cm –1 ), NO (1912 cm –1 ), HNCO (2265 cm –1 ), and NO/CO (1956–1800 cm –1 ). , FT-IR spectra show that the main gaseous products for thermal decomposition of ε-CL-20 are N 2 O, NO 2 , and HCN, which are also comparable with the literature…”

Section: Resultsmentioning

confidence: 78%

Preparation of CNTs Coated with Polydopamine–Ni Complexes and Their Catalytic Effects on the Decomposition of CL-20

et al. 2021

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To improve the condensed-phase reaction rate of ε-CL-20, polydopamine (PDA)−nickel complex-coated multiwalled carbon nanotubes (CNTs) have been prepared and used as combustion catalysts. The PDA−Ni complex has been prepared and in situ coprecipitated with ε-CL-20 by an antisolvent crystallization process in its dimethyl sulfoxide (DMSO) solution. It has been shown that crystalline CL-20 composites included with PDA−Ni complexes are polygon-shaped with a smooth surface and an average diameter of 10−15 μm, whereas it is 140 μm for raw ε-CL-20 crystals. The catalytic reactivity of the complex on thermolysis of CL-20 has been investigated using the differential scanning calorimetry (DSC) and thermogravimetry (TG)coupled Fourier transform infrared (FT-IR) spectroscopy technique. It has been found that CNT@PDA−Ni complexes have catalytic effects on the decomposition of ε-CL-20 by decreasing/shifting of the exothermic peak from T p = 240.1 to 238.7 °C. The FT-IR spectra of CL-20 decomposition products under the effect of the catalyst predominantly show peaks at 1274, 1644 and 1596, 1912, 2265, and 1956−1800 cm −1 , indicating the presence of fragments with N 2 O, NO 2 , NO, HNCO, and NO/CO, respectively. The change in the ε-CL-20 decomposition mechanism should be attributed to the catalytic action of CNT, decreasing the formation of NO 2 . Also, under the effect of the carbon-based catalyst, the HNCO formation was detected at another temperature in comparison with raw CL-20, with peak absorption at 224.1 vs 232.3 °C and the evolution was completed at 250.8 vs 246.2 °C, respectively.

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Section: Resultsmentioning

confidence: 78%

Preparation of CNTs Coated with Polydopamine–Ni Complexes and Their Catalytic Effects on the Decomposition of CL-20

et al. 2021

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“…This may be the reason for the appearance of wide endothermic peak with two different stages. For further confirmation, TG‐FTIR or similar technique are used . The initial mass loss corresponding to the first stage decomposition is about 35%, and it may be inferred that the N‐NO 2 bonds are dissociated first releasing both the nitro groups.…”

Section: Resultsmentioning

confidence: 99%

Decomposition Kinetics of Substituted Energetic Isowurtzitane Cage Molecules Hexanitrohexaazaisowurtzitane (CL‐20) and TEX: A Comparative Study

Vargeese

2019

ChemistrySelect

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N‐substituted hexa(N‐Nitro) compound 2,4,6,8,10,12‐Hexanitro‐2,4,6,8,10,12‐hexaazatetracyclo‐ [5.5.0.05,9.03,11] dodecane (HNIW or CL‐20) and the O‐substituted di(N‐Nitro)) compound 4,10‐dinitro‐2,6,8,12‐tetraoxa‐4,10‐diazatetracyclo[5.5.0.05,9.03,11]‐dodecane (TEX) are two interesting energetic Isowurtzitane cage molecules. To develop an understanding about the underlying phenomena during explosion/combustion, the thermal decomposition behaviour and kinetics of HNIW and TEX is studied. The solid phase decomposition of HNIW shows a dependence on the extent of reaction (α), while the liquid phase decomposition of TEX is independent of α. This point towards the multistep reaction kinetics involved in the HNIW decomposition and a single stage decomposition or unification of multistep reactions exhibited by TEX during the melt phase decomposition. However, the sublimation process in TEX is defined by different activation energy values. The experimental results are presented here and theoretical possibilities are being explored through quantum chemical studies. Our study aims to provide a link between the decomposition behaviour of Isowurtzitane cage molecules and their combustion behaviour.

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“… 45 , 46 . It is one of the most powerful and stable energetic compounds 47 . Compared to other high energy explosives, including HMX, RDX, and PETN, CL-20 has superior performance with respect to detonation velocity, detonation pressure, and enthalpy of formation 48 .…”

Section: Introductionmentioning

confidence: 99%

“…CL-20 also contains six nitro groups giving the molecule an excellent oxidizer to fuel ratio. The energy released through oxidation combined with the inherent strain energy gives CL-20 its higher detonation velocity and enthalpy of formation 47 .…”

Section: Introductionmentioning

confidence: 99%

Accelerated synthesis of energetic precursor cage compounds using confined volume systems

Brown

Doppalapudi

Fedick

2021

Sci Rep

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Confined volume systems, such as microdroplets, Leidenfrost droplets, or thin films, can accelerate chemical reactions. Acceleration occurs due to the evaporation of solvent, the increase in reactant concentration, and the higher surface-to-volume ratios amongst other phenomena. Performing reactions in confined volume systems derived from mass spectrometry ionization sources or Leidenfrost droplets allows for reaction conditions to be changed quickly for rapid screening in a time efficient and cost-saving manner. Compared to solution phase reactions, confined volume systems also reduce waste by screening reaction conditions in smaller volumes prior to scaling. Herein, the condensation of glyoxal with benzylamine (BA) to form hexabenzylhexaazaisowurtzitane (HBIW), an intermediate to the highly desired energetic compound 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), was explored. Five confined volume systems were compared to evaluate which technique was ideal for forming this complex cage structure. Substituted amines were also explored as BA replacements to screen alternative cage structure intermediates and evaluate how these accelerated techniques could apply to novel reactions, discover alternative reagents to form the cage compound, and improve synthetic routes for the preparation of CL-20. Ultimately, reaction acceleration is ideal for predicting the success of novel reactions prior to scaling up and determining if the expected products form, all while saving time and reducing costs. Acceleration factors and conversion ratios for each reaction were assessed by comparing the amount of product formed to the traditional bulk solution phase synthesis.

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Decomposition Mechanism of Hexanitrohexaazaisowurtzitane (CL-20) by Coupled Computational and Experimental Study

Cited by 30 publications

References 22 publications

Preparation of CNTs Coated with Polydopamine–Ni Complexes and Their Catalytic Effects on the Decomposition of CL-20

Preparation of CNTs Coated with Polydopamine–Ni Complexes and Their Catalytic Effects on the Decomposition of CL-20

Decomposition Kinetics of Substituted Energetic Isowurtzitane Cage Molecules Hexanitrohexaazaisowurtzitane (CL‐20) and TEX: A Comparative Study

Accelerated synthesis of energetic precursor cage compounds using confined volume systems

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