The creation of novel energetic polymers for future advanced solid composite propellants and gunpowder is an urgent area of modern research. A simple and effective waste-free cycloaddition reaction between dialkyne and diazide comonomers, both bearing nitramine groups, for the synthesis of an energetic polymer containing explosophoric units in the polymer chain has been described. Neither solvent nor catalyst is required for the production of this polymer, the comonomers used are readily available, and the product does not need any purification, and, importantly, this protocol scales well. The resulting polymer, C1Z1, (C14H22N12O8)(n), was comprehensively characterized by spectral and physico-chemical methods. Compatibility with energetic plasticizers (NG, DNDEG, DANPE), thermochemical characteristics and combustion features indicate the prospects of target polymer C1Z1 (density, rho = 1.484 g/cm(3); onset temperatures is 230 degrees C; positive enthalpy of the formation, Delta H-f(0) = +636 kJ/kg; burning rate at 10 MPa is 9.5 mm/s) as a binder base for energetic materials. Comparison of C1Z1 with nitrocellulose (NC) and their compositions with plasticizers revealed the advantages of C1Z1.

A series of R-[1,2,5]oxadiazolo[3,4-c]cinnoline 5-mono- and 1,5-dioxides containing substituents (R = CH3, F, Br, CF3) at different positions were synthesized by an N-nitration-annulation process occurring upon treatment of 3-amino-4-(R-aryl)furazans and 4-amino-3-(R-aryl)furoxans with the HNO3-H2SO4-Ac2O system. The regioselectivity of the ring closure step was determined for the unsymmetrically substituted R-aryl precursors. Unexpected acylation at position 6 of 7-bromo-[1,2,5]oxadiazolo[3,4-c]cinnoline 5-oxide occurred as a result of the increased duration of the synthesis. The crystal structures of five new compounds were determined by X-ray diffraction analysis, and their crystal packings were compared with each other and with those of previously studied molecules, revealing common motifs regardless of the type or position of the substituent. Specifically, the fluorine derivative forms layers isostructural with those in unsubstituted mono- and dioxides, differing only in their arrangement within the P21 and P21/c space groups. Two methyl derivatives, on the other hand, exhibit a structure with flat layers. While the crystal environments of different R-substituents are generally distinct, the unsubstituted part of the heterocyclic core tends to form repeating isostructural motifs, such as dimers, chains, and layers. Although substituents disrupt the crystal packing, they still allow for the combination of these motifs in different crystal structures.

N-Nitro derivatives of primary alkyl, aryl and heteroarylamines can be directly alkylated with functionalized alcohols under Mitsunobu conditions at the N and/or O atoms of the nitramino moiety to give secondary nitramines or 1-alkoxydiazene 1-oxides, respectively.

A number of primary aryl nitramines have been synthesized in high yields by N-nitration of aryl amines bearing electron-withdrawing substituents. An optimized HNO3—Ac2O—AcOH nitrating system and a unified method for isolation and purification of the products were used.

The thermal decomposition of a number of analogues of hexanitrohexaazaisowurtzitan (CL-20), in where one or more N-nitro groups have been replaced by another explosophoric unit (diverse N-alkylnitramine groups or N- trinitroethyl), has been studied by methods of isothermal and non-isothermal kinetics. It was found that replacing the N-nitro group with even a more thermally stable substituent leads to a decrease in the stability of the nitrated hexaazaisowurtzitane framework. It was suggested that the substituent distorts the symmetry of the strained hexaazaisowurtzitane cage, which affects the strength of the N-NO2 bond. When a substituent less stable than the N-nitro group in the parent CL-20 is installed, the initial stage of degradation is determined by the decomposition kinetics of this substituent. One of the objects of this study, 4,10-dinitro-2,6,8,12-tetrakis(2,2,2-trinitroethyl) -2,4,6,8,10,12-hexaazaisowurtzitane (8), was synthesized for the first time; it was fully characterized and also confirmed by X-ray structural data.

While the effect of isomerism on the properties of energetic molecules has long been recognized, the use of this phenomenon to deliberately improve the performance of energetic materials has now been approached. Here, we report the development of effective protocols for the preparation of isomeric energetic compounds with a furazan-triazole-pyrazole framework, which differ in the binding points of these subunits and in the position of the nitro group. The two synthesized isomers readily form X-ray quality crystals of solvates with DMSO and water, but only one isomer was able to give unsolvated crystals. Significant differences in molecular geometry and noncovalent interactions due to the effect of the solvent incorporated into the crystal lattice are highlighted. The ambiguity of evaluating structure-property relationships for a single compound from the X-ray data of its solvate is demonstrated. The isomer synthesized for the first time, 3-(5-(5-(3,4-dinitro-1H-pyrazol-5-yl)-1H-1,2,4-triazol-3-yl)-4-nitrofurazan (6), is of greater interest because, unlike the other isomer, it is not hygroscopic and has a higher density. Isomer 6 has a shock sensitivity and detonation velocity similar to those of RDX, but it is more thermally stable and insensitive to friction.

In the presence of alkali in DMF, propargyl bromide and propargyl tosylate participate in the N- and O-alkylation of the nitramino group, giving N—R—N-propargylnitramines and 1-propargyloxy-2-R-diazene 1-oxides. Most of O-propargyl derivatives are unstable and decompose in the reaction medium; however, an O-propargylation product was isolated. All products were characterized by multinuclear NMR spectroscopy. Two compounds were studied by X-ray diffraction analysis.

From bromomethyl ketones to aminofurazans – a simple, effective and inexpensive synthesis.

3-Amino-4-R-furazans can be converted into the corresponding 3-difluoroamino-4-R-furazans by fluorination with a fluorine—argon mixture under both liquid-phase and solid-phase conditions. Fluorinations can be enabled in the presence of both electron-donating and electron-withdrawing substituents R; some substituents R underwent transformations under fluorination conditions.

Using SC XRD, it was proved that the cyclocondensation of 3,4-diaminofurazan with diethyl-2-oxosuccinate gives two products, being structural isomers – derivatives of furazano[3,4- b ]pyrazin-6-one (2) and furazano[3,4- b ][1,4]diazepin-7-one (6).

Oxidation of 4H,8H-bis(1,2,5-oxadiazolo)[3,4-b:3 ',4 '-e]pyrazine H2L in the presence of Ba or Ca oxide leads to the formation of paramagnetic Ba(II) and Ca(II) salts, respectively. It was shown that the basicity of the reaction mixture plays an important role in the oxidation of H2L. Molecular and crystal structures of [Ba(L)(2)(H2O)(5)]2H(2)O, [Ba-2(L)(HL)(2)(H2O)(6)](L)4H(2)O, [Ba(HL)(H2O)(6)](HL)H2O, and [Ca(L)(H2O)(6)](2)Br-2 were determined. It was found that paramagnetic [Pb(L)(2)(H2O)(5)]2H(2)O can be obtained by H2L oxidation with PbO2 in the absence of alkaline earth metal oxides. It was shown that using two oxidizing agents, PbO2 and Br-2, in the reaction of BaO with H2L allows us to obtain paramagnetic salts with a new anion radical bis(1,2,5-oxadiazolo)[3,4-b:3 ',4 '-e]pyrazine-4-oxyl (L-O) and "singlet diradical" L-O1. It was found that, depending on the synthetic conditions, [Ba(L-O)(2)(H2O)(6)]2H(2)O crystallizes in the form of several polymorphic modifications differing in the angles between the planes of L-O radicals bound to the Ba ion. Quantum chemical analysis revealed that the presence of the N-oxide fragment in L-O leads to a noticeable redistribution of the spin density in comparison with L. The calculated map of the distribution of exchange integrals at different relative displacements in pairs of L-O allows us to give a qualitative insight into the magnetic behavior of anion radical stacks.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The syntheses and characterization of novel propargyl ethers of N-(hydroxymethyl)nitramines that contain from one to four nitramine units are reported. All nitramine-functionalized ethers were well characterized by IR and multinuclear NMR spectroscopy as well as CHN analysis, and the X-ray crystal structures of two of them are described. For ethers bearing two or three nitramine units, the standard molar enthalpies of formation at 298.15 K were determined from the experimental standard molar energies of combustion in oxygen measured by static bomb combustion calorimetry

A [3 + 2] cycloaddition reaction using dialkyne and diazide comonomers, both bearing explosophoric groups, to synthesize energetic polymers containing furazan and 1,2,3-triazole ring as well as nitramine group in the polymer chain have been described. The developed solvent- and catalyst-free approach is methodologically simple and effective, the comonomers used are easily available, and the resulting polymer does not need any purification. All this makes it a promising tool for the synthesis of energetic polymers. The protocol was utilized to generate multigram quantities of the target polymer, which has been comprehensively investigated. The resulting polymer was fully characterized by spectral and physico-chemical methods. Compatibility with energetic plasticizers, thermochemical characteristics, and combustion features indicate the prospects of this polymer as a binder base for energetic materials. The polymer of this study surpasses the benchmark energetic polymer, nitrocellulose (NC), in a number of properties.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Difluoroamination and esterification reactions were utilized for the preparation of NF2-analogs of 2,2,2-trinitroethyl 4,4,4-trinitrobutanoate with replacing one or two nitro groups. Difluoroamino products possess promising properties as ingredients of metallized energetic materials.

Energetic ionic liquids (EILs) have drawn considerableattentionas potential liquid propellant components. However, most known EILsare oxygen-deficient and can be used only with external oxidizer.Herein, we report the first example of energetic mesoionic liquid, 3-methylazasydnone, that can function both as a monopropellantand in bipropellant systems. Methylazasydnone has the highest densityamong the methylated five-membered aromatic heterocycles in the liquidand solid state (1.49 and 1.60 g cm(-3), respectively),shows moderate volatility, good thermal stability, and is insensitiveto impact. The computed performance of liquid propellant'scombustion is superior to that of the benchmark energetic ionic liquid,2-hydroxyethylhydrazinium nitrate (428 vs 424 g & BULL;s cm(-3)). Overall, methylazasydnone is a promising advanced functional materialfor application in green liquid mono- and bipropellants.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.