Nitro-, Cyano-, and Methylfuroxans, and Their Bis-Derivatives: From Green Primary to Melt-Cast Explosives

Abstract

In the present work, we studied in detail the thermochemistry, thermal stability, mechanical sensitivity, and detonation performance for 20 nitro-, cyano-, and methyl derivatives of 1,2,5-oxadiazole-2-oxide (furoxan), along with their bis-derivatives. For all species studied, we also determined the reliable values of the gas-phase formation enthalpies using highly accurate multilevel procedures W2-F12 and/or W1-F12 in conjunction with the atomization energy approach and isodesmic reactions with the domain-based local pair natural orbital (DLPNO) modifications of the coupled-cluster techniques. Apart from this, we proposed reliable benchmark values of the formation enthalpies of furoxan and a number of its (azo)bis-derivatives. Additionally, we reported the previously unknown crystal structure of 3-cyano-4-nitrofuroxan. Among the monocyclic compounds, 3-nitro-4-cyclopropyl and dicyano derivatives of furoxan outperformed trinitrotoluene, a benchmark melt-cast explosive, exhibited decent thermal stability (decomposition temperature >200 °C) and insensitivity to mechanical stimuli while having notable volatility and low melting points. In turn, 4,4′-azobis-dicarbamoyl furoxan is proposed as a substitute of pentaerythritol tetranitrate, a benchmark brisant high explosive. Finally, the application prospects of 3,3′-azobis-dinitro furoxan, one of the most powerful energetic materials synthesized up to date, are limited due to the tremendously high mechanical sensitivity of this compound. Overall, the investigated derivatives of furoxan comprise multipurpose green energetic materials, including primary, secondary, melt-cast, low-sensitive explosives, and an energetic liquid.

Nitrile Oxide, Alkenes, Dipolar Cycloaddition, Isomerization and Metathesis Involved in the Syntheses of 2-Isoxazolines

“…It should be added that RCNO dimerization to furoxanes is not only a side reaction accompanying cycloaddition but also an important method of furoxane synthesis [ 156 , 296 ]. These compounds are attractive as pharmaceuticals [ 297 ] or even as explosive materials [ 298 ].…”

A Short Review of Nitric Esters and Their Role in Energetic Materials

“…Standalone melt-castable material 10 was recently synthesized, in which the well-known furoxan ring was inserted between the 5-nitroxymethyl isoxazole rings (Figure ). When comparing 10 to BIDN, introduction of the furoxan ring was observed to significantly increase the density, heat of formation, detonation velocity, and detonation pressure (Table ).…”

Recent Advances in the Synthesis and Biomedical Applications of Heterocyclic NO-Donors

“…Recently, a biomedical application of diacylfuroxans as precursors to nitrile oxides capable of covalent inhibition of glutathione peroxidase 4 (GPX4) to induce ferroptosis was revealed [ 117 ]. Application of furoxan-based compounds as high-energy materials, primary or secondary explosives, propellants or rocket fuels was also reported numerously [ 118 , 119 , 120 , 121 , 122 ].…”