Hydrogen Bonding in CHON-Containing Energetic Crystals: A Review

Crystal Growth & Design, Journal Year: 2019, Volume and Issue: 19(10), P. 5981 - 5997

Published: Sept. 9, 2019

Hydrogen bonding (HB) universally exists in CHON-containing energetic materials (EMs) and significantly influences their structures, properties, performances. As time proceeds, some new types of EMs such as cocrystals (ECCs) ionic salts (EISs) are thriving currently richening insight into the HB EMs, these reviewed this article well. The intramolecular mostly stable molecules while seldom less molecules; weak abundant HBs dominate intermolecular interactions consolidate crystal packing. For ECCs with neutral heterogeneous molecules, serve one strategies for design. In comparison, EISs greatly strengthened polarity increases ionization. A strong usually enhances molecular stability large π-bonds packing coefficients facilitates reversible H transfer, which is advantageous low mechanical sensitivity. HB-aided π–π stacking that favors sensitivity observed all three kinds including traditional homogeneous EISs. However, a an EM causes ready thereby worsening thermal stability. Thus, influence on can go both ways, there should be balance when HB-containing designed.

Language: Английский

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Review of the molecular and crystal correlations on sensitivities of energetic materials

Journal of Hazardous Materials, Journal Year: 2020, Volume and Issue: 398, P. 122910 - 122910

Published: May 14, 2020

Language: Английский

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π–π Stacking Contributing to the Low or Reduced Impact Sensitivity of Energetic Materials

Crystal Growth & Design, Journal Year: 2020, Volume and Issue: 20(5), P. 2824 - 2841

Published: April 15, 2020

π–π stacking, usually together with the aid of hydrogen bonding (HB), serves as a main characteristic low impact, sensitive, highly energetic materials (LSHEMs), which are desired for application, and attracts considerable attention in designing synthesizing new EMs. This Perspective highlights progress insights into stacking EMs, covering traditional crystals homogeneous neutral molecules, cocrystals (ECCs), ionic salts (EISs). A rather large π-bond is requisite can be classified four patterns, including face-to-face wavelike crossing mixing an increasing difficulty shear sliding, HB plays important role supporting sliding layers. Straightforwardly, pattern–impact sensitivity relationship rooted steric hindrance when preferred to design LSHEMs at crystal level, due least or lowest barrier among patterns. has been extensively observed ECCs, EISs, enlightening us make rule EMs such stacking. However, it still difficult rule, attributed unclear between molecular structures. Maybe, will become increasingly feasible achieve by establishing database detailed information on molecules related amount data collecting experimental predicted results, combining advanced machine learning technologies. Combining this article recent review (Cryst. Growth Des. 2019, 19 (10), 5981–5997), overall perspective intermolecular interactions C, H, O, N atoms could have presented.

Language: Английский

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1,3,5-Triamino-2,4,6-Trinitrobenzene (TATB): Enlightening the way to create new Low-Sensitivity and High-Energy materials from a viewpoint of multiscale

Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: 490, P. 151737 - 151737

Published: April 27, 2024

Language: Английский

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New Thermolysis Routes of Diaminodinitroethylene (DADNE)

Propellants Explosives Pyrotechnics, Journal Year: 2021, Volume and Issue: 46(7), P. 1079 - 1096

Published: March 31, 2021

Abstract Primary steps of thermolysis the promising high‐energy compound 1,1‐diamino‐2,2‐dinitroethylene (DADNE or FOX‐7) were studied by quantum‐chemical methods using PBE0 hybrid functional in cc‐pVDZ basis set and coupled‐cluster method at CCSD/aug‐cc‐pVDZ level. A series thermal decomposition reactions studied. The proceeding via hydrogen transfer from amino group to carbon, along with four variants transformations aci form DADNE insufficiently earlier, are shown be most energetically favorable channels decomposition. activation enthalpies ΔH a all these close reliable experimental values which range 190–200 kJ mol −1 .

Language: Английский

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Reversible intramolecular hydrogen transfer: a completely new mechanism for low impact sensitivity of energetic materials

Physical Chemistry Chemical Physics, Journal Year: 2019, Volume and Issue: 21(5), P. 2397 - 2409

Published: Jan. 1, 2019

The intramolecular H transfer of energetic NO₂-compounds has been recognized as a possible primary step in triggering molecular decomposition for long time.

Language: Английский

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Alternative mechanism of thermolysis of diaminodinitroethylene (FOX-7)

Russian Chemical Bulletin, Journal Year: 2021, Volume and Issue: 70(2), P. 424 - 426

Published: Feb. 1, 2021

Language: Английский

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Difference in the Thermal Stability of Polymorphic Organic Crystals: A Comparative Study of the Early Events of the Thermal Decay of 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) Polymorphs under the Volume Constraint Condition

The Journal of Physical Chemistry C, Journal Year: 2019, Volume and Issue: 123(27), P. 16565 - 16576

Published: June 19, 2019

Polymorphism is universal in organic crystals like conventional energetic materials (EMs), and it may cause a difference thermal stability, one of the most important properties EMs. Nevertheless, deep insights into differences polymorphic EMs are lacking. 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) powerful EM commercialized already possesses three polymorphs stabilized at common condition, which exhibit many performances. However, underlying mechanism responsible for these remains unclear. In this work, self-consistent charge density functional tight binding scheme molecular dynamics simulations combined to reveal decay CL-20, with considerations an extreme volume constraint two heating types. The lower activity ε-CL-20 distinguished from β- γ-CL-20 relatively low temperature 1000 K, as only does not decompose time scale simulation 20 ps. partly its impact sensitivity. Two high temperatures 1500 2000 K cannot differentiate their activities. Moreover, unimolecular N–N breakage governs first steps all polymorphs. Five types bond cleavages, including NO2 partitions 5- 6-membered rings, cleavage C–N bonds C–C breakage, observed decay. Interestingly, five ignitions be any case. Besides, we find that disfavors formation stable products N2 CO2. These results expected give complicated sensitivity

Language: Английский

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Heat-Induced Polymorphic Transformation Facilitating the Low Impact-Sensitivity of 2,2-Dinitroethylene-1,1-diamine (FOX-7)

The Journal of Physical Chemistry C, Journal Year: 2019, Volume and Issue: 123(26), P. 16014 - 16022

Published: June 10, 2019

The intermediate structures for an energetic material (EM) loaded until the final decay are often inaccessible and overlooked, while they a determining factor of property performance, with similar importance original structure under common conditions. present work exemplifies by revealing low impact sensitivity 2,2-dinitroethylene-1,1-diamine (FOX-7) consideration heat-induced polymorphic transformation. Checking packing polymorph at ambient conditions (α-form) two ones (β- γ-forms) FOX-7, we confirm that heating makes shear sliding increasingly ready. That is, from α- to β- γ-FOX-7, crystal varies wavelike shape face-to-face one, increase molecular planarity, as their maximal torsion angles O–N–C–C decrease 35.6 25.6 20.2°; shear-sliding barriers reduce ready ranges in same order, verified density functional theory calculations. This transformation FOX-7 π–π stacking is responsible its sensitivity, remedying disadvantage relatively thermal stability. Hardly, will understand impact-sensitivity if α-form considered alone. presents exact example show intermediates produced external stimuli on EM understanding performance. It also shows complexity mechanism EMs some possible deficiencies caused considering initial unloaded case

Language: Английский

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An ab initio deep neural network potential to study the effect of density on the thermal decomposition mechanism of FOX-7

The Journal of Chemical Physics, Journal Year: 2025, Volume and Issue: 162(11)

Published: March 18, 2025

Condensed phase explosives typically contain defects such as voids, bubbles, and pores; this heterogeneity facilitates the formation of hot spots triggers decomposition reaction at low densities. The study thermal mechanisms different densities has thus attracted considerable research interest. Gaining a deeper insight into these would be helpful for elucidating detonation processes explosives. In work, we developed an ab initio neural network potential FOX-7 system using machine learning method. Extensive large-scale (1008 atoms) long-duration (nanosecond timescale) deep molecular dynamics simulations were performed to investigate effect density on mechanism. results indicate that initial pathway is cleavage C–NO2 bond densities, while frequency decreases higher density. Increasing significantly increases rate during final products. However, it leads decrease in released heat minimal impact temperature. addition, by analyzing trajectories conducting quantum chemical calculations, identified two lower-barrier production pathways produce CO2 N2.

Language: Английский

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