Polynitro Containing Energetic Materials based on Carbonyldiisocyanate and 2, 2-Dinitropropane-1, 3-diol

Chemical Descriptors for a Large-Scale Study on Drop-Weight Impact Sensitivity of High Explosives

The drop-weight impact test is an experiment that has been used for nearly 80 years to evaluate handling sensitivity of high explosives. Although the results of this test are known to have large statistical uncertainties, it is one of the most common tests due to its accessibility and modest material requirements. In this paper, we compile a large data set of drop-weight impact sensitivity test results (mainly performed at Los Alamos National Laboratory), along with a compendium of molecular and chemical descriptors for the explosives under test. These data consist of over 500 unique explosives, over 1000 repeat tests, and over 100 descriptors, for a total of about 1500 observations. We use random forest methods to estimate a model of explosive handling sensitivity as a function of chemical and molecular properties of the explosives under test. Our model predicts well across a wide range of explosive types, spanning a broad range of explosive performance and sensitivity. We find that properties related to explosive performance, such as heat of explosion, oxygen balance, and functional group, are highly predictive of explosive handling sensitivity. Yet, models that omit many of these properties still perform well. Our results suggest that there is not one or even several factors that explain explosive handling sensitivity, but that there are many complex, interrelated effects at play.

A promising insensitive energetic material based on a fluorodinitromethyl explosophore group and 1,2,3,4-tetrahydro-1,3,5-triazine: synthesis, crystal structure and performance

The introduction of fluorodinitromethyl energetic groups is an efficient strategy to improve the performances of energetic materials. In this paper, an insensitive energetic compound 6-(fluorodinitromethyl)-3-nitro-1,2,3,4-tetrahydro-1,3,5-triazine (FMTNT) was designed and synthesized based on the modification of 1,3,5-triazine backbone via the nitration-rearrangement, reduction and fluorination sequence. The single crystal of FMTNT was firstly obtained and determined, meanwhile, this novel structure was also fully characterized by the methods of IR, 1H NMR, 13C NMR, 19F NMR and elemental analysis. Studies on thermal behaviors and detonation performances of FMTNT were also carried out through differential scanning calorimetry (DSC-TG) approach and EXPLO5 program, respectively. The decomposition temperature of FMTNT is found to be at 157.5 °C via thermal chemical analysis and the detonation performances were proved to be good, with a detonation velocity of 8624.8 m s-1 and detonation pressure of 29.1 Gpa. Furthermore, the experimental results showed that impact and friction sensitivity reaches 20 J and 240 N, even less sensitive than TNT, indicating a broad perspective in the application of insensitive explosives and propellants.

Axial substitution of a precursor resulted in two high-energy copper(ii) complexes with superior detonation performances

The design and synthesis of explosives with high performance, good thermal stability, and low sensitivity is an important subject for the development of energetic materials. Energetic complexes have recently emerged as a promising energetic material form. As one of the representatives, [Cu(Htztr)₂(H₂O)₂]_n (H₂tztr = 3-(1H-tetrazol-5-yl)-1H-triazole) was previously reported with good energetic performance, outstanding thermostability (T_dec = 345 °C) and low sensitivity to impact and friction stimuli. However, due to the existence of water molecules, its effective energy density is remarkably decreased, resulting in a diminished detonation performance. In order to further improve the detonation performance, using [Cu(Htztr)₂(H₂O)₂]_n as a precursor, {[Cu(Htztr)(H₂O)]NO₃}_n (1) and [Cu(H₂tztr)₂(HCOO)₂]_n (2) were synthesized by the axial substitution reaction with NO₃^- and HCOO^-. The structures of 1 and 2 were characterized by single crystal X-ray diffraction. Both of them exhibit high thermal stabilities and insensitivities to impact and friction. Moreover, the same DFT calculation methodology shows that the heat of detonation of 2 (3.5663 kcal g^-1) is significantly higher than that of the precursor [Cu(Htztr)₂(H₂O)₂]_n (2.1281 kcal g^-1). Meanwhile, the empirical Kamlet-Jacobs equations were used to theoretically predict the detonation properties of the title complexes, and the results show that 1 and 2 have excellent detonation velocity (D) and detonation pressure (P).

The energetic 3-trinitromethyl-5-nitramino-1H-1,2,4-triazole and nitrogen-rich salts

An oxygen- and nitrogen-rich energetic triazole as an excellent example with outstanding performance but high sensitivity, which can be adjusted by the formation of nitrogen-rich salts.

Through-space (19) F-(15) N couplings for the assignment of stereochemistry in flubenzimine

Through-space (19) F-(15) N couplings revealed the configuration of flubenzimine, with the CF3 group on N4 pointing towards the lone pair of N5. The (19) F-(15) N coupling constants were measured at natural abundance using a spin-state selective indirect-detection pulse sequence. As (15) N-labelled proteins are routinely synthesized for NMR studies, through-space (19) F-(15) N couplings have the potential to probe the stereochemistry of these proteins by (19) F labelling of some amino acids or can reveal the site of docking of fluorine-containing drugs. Copyright © 2016 John Wiley & Sons, Ltd.

High-density insensitive energetic materials: 2,4,6-tris(2-fluoro-2,2-dinitroethoxy)-1,3,5-triazine

A Na₃PO₄-promoted nucleophilic substitution of all chlorine atoms of cyanuric with fluorodinitroethanol was achieved with excellent yield. The product demonstrates promising potential for diverse applications like explosives or propellants.

Novel trinitroethanol derivatives: high energetic 2-(2,2,2-trinitroethoxy)-1,3,5-triazines

The multicomponent reaction of 2,4,6-trichloro-1,3,5-triazine with potassium trinitromethane and trinitroethanol was exploited for the first synthesis of the hetaryl trinitroethyl ethers.