Hexanitrohexaazaisowurtzitane (HNIW, CL-20)

Viswanath, Dabir S.; Ghosh, Tushar K.; Boddu, Veera M.

doi:10.1007/978-94-024-1201-7_2

Cited by 16 publications

(12 citation statements)

References 55 publications

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“…The density of nitramines increases with increasing molecular rigidity [ 11 ]. One notable example is hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.0 3,11 .0 5,9 ]dodecane (hexanitrohexaazaisowurtzitane, CL-20) ( Figure 1 ), which exhibits one of the highest detonation velocities (V 0 D = 9.36 (ε) km/s) among all of the explosives, and the highest density among the known nitranmines (ρ = 2.044 g/cm 3 ) [ 12 , 13 , 14 , 15 ], as well as a positive enthalpy of formation (ΔH f = 454 kJ/mol), optimal oxygen balance (−11.0) and detonation pressure (420 kbar) [ 16 , 17 , 18 , 19 , 20 , 21 ]. CL-20 excels compared to the other high-energy explosive materials such as HMX, RDX, PETN, etc.…”

Section: Introductionmentioning

confidence: 99%

Acid-Catalyzed Condensation of Benzamide with Glyoxal, and Reaction Features

et al. 2022

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Scholars from around the world have been attempting to simplify and cheapen the synthetic method for the promising high-energy compound CL-20 for decades. The lack of understanding of the formation mechanisms of hexaazaisowurtzitane derivatives―CL-20 precursors―is a barrier to solving the said problems. Here, we report the results from an in-depth study into the acid-catalyzed condensation between benzamide and glyoxal in a molar ratio of 2:1 in polar protic and aprotic solvents. Sixteen compounds were isolated and identified, of which eight were synthesized for the first time. A geminal diol, N,N’-(2,2-dihydroxyethane-1,1-diyl)dibenzamide, was synthesized. Two isomers of 1,2-bis(benzoylamino)-1,2-ethanediol were isolated and identified. N,N’-(1-oxoethane-1,2-diyl)dibenzamide and 2-oxo-2-[(phenylcarbonyl)amino]ethyl benzoate were produced that were likely formed due to the 1,2-hydride shift. N-polysubstituted 1,4-dioxane-2,3,5,6-tetramine was synthesized for the first time, whose structure may be of interest as a scaffold for new explosives. DMSO, THF and HCOOH were found to be able to engage in a reaction with benzamide, or condensation products thereof, and glyoxal under acid-catalyzed conditions.

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Section: Introductionmentioning

confidence: 99%

Acid-Catalyzed Condensation of Benzamide with Glyoxal, and Reaction Features

et al. 2022

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“…The structure of CL-20 is a polycyclic nitramine cage whose basic cage structure is formed from the condensation of glyoxal and benzylamine (BA) to produce hexabenzylhexaazaisowurtzitane (HBIW) 49 , 50 . The reaction for preparing HBIW is performed in an organic solvent, typically acetonitrile, and in the presence of an acid catalyst, typically formic acid (FA) 46 , 49 , 51 . The reaction mechanism for preparing HBIW involves several known intermediate structures that contain a dicarbinolamine or diimine functional groups 46 , 50 , 52 .…”

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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“…Update of energetic materials is an important indicator of update of weapons. 2,4,6,8,10,4,6,8,10, is the most outstanding nitroamine explosive with the highest density, the highest detonation velocity, the highest explosion heat, and high oxygen balance (OB). 1,2 It has cage-like molecular structure, which results in very high molecular tension.…”

Section: Introductionmentioning

confidence: 99%

“…One is the preparation of eutectic materials, that is, CL-20 co-crystallizes with a very insensitive explosive crystal to form an insensitive co-crystal. Ghosh and coworkers prepared CL-20/HMX co-crystal through solvent evaporation and proved that the performance of CL-20/ HMX eutectic is more stable than CL-20 4 ; another discovery is that nano explosives have obviously lower sensitivities than the micron explosives. 5 So there are many researchers who try to fabricate nano-CL-20 by different methods.…”

Section: Introductionmentioning

confidence: 99%

Characteristics and properties of nitrocellulose/glycidyl azide polymer/2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane nanocomposites synthesized using a sol–gel supercritical method

Wang

Zhang

Song

et al. 2019

Nanomaterials and Nanotechnology

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nanoparticles uniformly embedded in nitrocellulose/glycidyl azide polymer matrix, were synthesized using a sol-gel supercritical method. The micron morphology, crystal phase, molecular structure, specific surface area, and surface elements were characterized using scanning electron microscopy, X-ray diffractometry, infrared, Brunauer-Emmett-Teller, and X-ray photoelectron spectroscopy analyses, respectively. Thermal analyses were performed, and the kinetic and thermodynamic parameters, such as activation energy, per-exponent factor, rate constant, activation heat, activation free energy, and activation entropy, were calculated. The decomposition products of the nitrocellulose/glycidyl azide polymer matrix and nitrocellulose/glycidyl azide polymer/2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane were also investigated by differential scanning calorimetry-infrared analysis. The result indicated that the main decomposition product of nitrocellulose/glycidyl azide polymer is carbon dioxide and theN 3 group in glycidyl azide polymer decomposed to nitrogen without being detected by infrared spectrometer; the main decomposition products of nitrocellulose/glycidyl azide polymer/2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane are carbon dioxide, nitrous oxide, and water, and few carbon monoxide, methane, and nitrogen oxide are also detected. Energy performances of nitrocellulose/glycidyl azide polymer matrix and nitrocellulose/glycidyl azide polymer/2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane nanocomposites were evaluated, that is, the parameters such as standard specific impulse, characteristic speed, combustion chamber temperature, average molecular weight of combustion products, and explosion heat were calculated. The results illustrated that as the weight percentage of nitrocellulose increases, the values of standard specific impulse, characteristic speed, average molecular weight of combustion products, combustion chamber temperature, and explosion heat increase. This was ascribed to that the oxygen balance of glycidyl azide polymer is substantially lower than that of nitrocellulose, which results in that the chemical energy of glycidyl azide polymer does not release sufficiently. Additionally, as weight percentage of glycidyl azide

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Hexanitrohexaazaisowurtzitane (HNIW, CL-20)

Cited by 16 publications

References 55 publications

Acid-Catalyzed Condensation of Benzamide with Glyoxal, and Reaction Features

Acid-Catalyzed Condensation of Benzamide with Glyoxal, and Reaction Features

Accelerated synthesis of energetic precursor cage compounds using confined volume systems

Characteristics and properties of nitrocellulose/glycidyl azide polymer/2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane nanocomposites synthesized using a sol–gel supercritical method

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