The huge demand for high-energy-density materials in many application fields determines the importance of developing new such materials and researching their properties. The paper deals with the properties of several promising high-energy tetracyclic compounds annelated with imidazole nitro derivatives and their study by quantum-chemical methods using the Gaussian 09 and NWChem software packages. We compute the enthalpy of formation using the atomization method and the method of reactions and analyze how the enthalpy of formation depends on the structural parameters of the compounds. Also, we compute the optimized structures and IR absorption spectra. Furthermore, we compare the Gaussian 09 and NWChem quantum-chemical programs regarding efficiency, parallelization, and computational requirements.

To design high-energy-density materials of a new level, it is necessary to develop methods for the functionalization of energetic scaffolds, which will make it possible to tune their physicochemical and energetic properties. For this reason, we have elaborated an approach for synthesizing a new series of energetic cage compounds with advanced properties by introducing the N-cyano group into the polynitro hexaazaisowurtzitane framework. The structures of the obtained substances were fully characterized with a combination of methods, including multinuclear (H-1, C-13{H-1}, N-14, and N-15{H-1}) NMR and IR spectroscopy, high-resolution mass spectrometry, X-ray diffraction analysis, electron microscopy and quantum chemical calculations. For the resulting compounds, thermal stability and safety tests were carried out, calorimetric and pycnometric measurements were performed, and the energetic potential was determined by high-temperature chemical equilibrium thermodynamic calculations. The new cyano derivatives have an acceptable density (up to 1.92 g cm(-3)) and a high enthalpy of formation (up to 2 MJ kg(-1)), which is 2 times that of the benchmark CL-20. The resistance of the target compounds to friction (up to 220 N) is the highest compared to CL-20 and its known analogues. 4,10-Dicyano-2,6,8,12-tetranitro-2,4,6,8,10,12-hexaazaisowurtzitane of the new series is the most thermally stable (a T-dec of 238 degrees C) among the known energetic polynitro hexaazaisowurtzitanes and is the first derivative of this family to surpass CL-20 in heat resistance. Moreover, the specific impulse for the novel materials showed an improvement of 6.5-13 s over CL-20.

High-energy density materials are widely used in various application areas, which makes the creation of new materials and study of their properties an important task. The paper addresses to the study of properties of a number of promising high-energy tetracyclic compounds annelated with pyrrole nitro derivatives, by quantum-chemical methods within the Gaussian 09 software package. Optimized structures, enthalpies of formation, and IR absorption spectra have been calculated for existing and not yet synthesized compounds. Dependence of the enthalpy of formation on the structural parameters of the compounds has been analyzed. The energy potential of the studied compounds has been initially assessed.

The kinetics of thermal decomposition of cage hydrocarbons, specifically exo-tricyclo[5.2.1.02.6]decane (exo-TCD) and exo,endo-tetracyclo[5.3.1.02,6.08,10]undecane (TCU-1, a monocyclo­propanated analog of exo-TCD), as well as their mixture (1 : 3 w/w) has been investigated. These compounds were compared in terms of thermal stability. The molar concentrations of the resultant gaseous products were determined experimentally. The equilibrium composition of the decomposition products was quantified, and the thermal effects of the thermal decomposition under thermodynamic and kinetic reaction control were identified.

Novel energetic furazans 3a–3c and 4a–4c containing isomeric (3,4-dinitro-1H-pyrazol-1-yl)-NNO-azoxy and (3,5-dinitro-1H-pyrazol-1-yl)-NNO-azoxy moieties have been obtained. A synthetic approach to aminofurazans 3a and 4a involves the reaction of 1-amino-3,4-dinitro-1H-pyrazole or 1-amino-3,5-dinitro-1H-pyrazole with 2,2,2-trifluoro-N-(4-nitrosofurazan-3-yl)acetamide and dibromoisocyanuric acid, followed by removal of the trifluoroacetyl group. Transformations of the amino group in aminofurazans 3a and 4a gave the corresponding nitro (3b, 4b) and azo (3c, 4c) substituted furazans. The compounds synthesized exhibit high experimental enthalpies of formation (2093–2847 kJ·kg−1), good thermal stabilities (onset decomposition temperatures 203–228 °C), acceptable densities (1.78–1.87 g·cm−3) and high detonation parameters (detonation velocities D = 8.71–8.99 km s−1, detonation pressures p = 33.9–38.7 GPa). Nitro substituted furazans 3b, 4b and azo substituted furazans 3c, 4c have been evaluated as effective energetic fillers for solid composite propellants, providing specific impulse values 9–11 s higher than similar formulations based on RDX and HMX, and 4–6 s higher than similar formulations based on CL-20.

New energetic materials based on N , N ′-methylene bridged polyfunctionalized cage compounds are reported in which derivatives of bis(polynitrohexaazaisowurtzitanyl)methane have both a higher enthalpy of formation and a lower friction sensitivity than CL-20.

Изучена термическая стабильность N-аллильных производных 7 Н - дифуразанофуроксаноазепина и 7 Н - трифуразаноазепина в неизотермическом и изотермическом режимах. Определены формально-кинетические закономерности распада и температурные зависимости констант скоростей реакций. Сопоставлена термическая стабильность аллильных и аминных производных азепинов.

Six novel energetic furazans containing tetrazol-5-yl-NNO-azoxy moiety were synthesized using (cyano-NNO-azoxy)-furazans as starting compounds. The obtained compounds exhibit high enthalpies of formation (531–792 kcal kg–1), acceptable densities (1.70–1.76 g cm–3), good thermal stability (Tonset = 146–199 °C), and, as a result, excellent detonation performance (detonation velocities of 8.61–8.95 km s−1 and detonation pressures of 31.6–36.0 GPa).

The work addresses to the study of the molecular and crystal structure and properties of a new energy-intensive compound 3,6-bis(2,2,2-trinitroethylnitramino)-1,2,4,5-tetrazine (NBTAT), first obtained by the authors in 2020. NBTAT compound crystallizes in the monoclinic system, space group P2(1)/n, density at room temperature 1.939 g/cm3. The energies of crystal packing and pairwise intermolecular interactions in NBTAT and its unnitrated analogue BTAT were calculated, and their comparative analysis was carried out. The enthalpy of formation of NBTAT molecules was calculated by quantum-chemical methods using Gaussian 09, and the enthalpy of formation of NBTAT in the solid phase (618 kJ/mol) was estimated. The energy capabilities of NBTAT as an oxidizer of solid composite propellants are estimated. It is shown that in metal-free compositions NBTAT is significantly superior to ammonium perchlorate (AP), dinitramide ammonium salt (ADN), HMX, BTAT at all stages of rocket systems, and is comparable to the superdense CL-20 yielding to the latter at the lower stages and slightly winning at the upper stages.

The work addresses to the study of the structure and thermochemical properties of a new high-enthalpy compound 3,6-bis(2,2,2-trinitroethylnitramino)-1,2,4,5-tetrazine (NBTAT), first obtained in the IPCP RAS in 2020. The enthalpy of formation of NBTAT, IR absorption spectra and molecule structure were calculated by various ab initio quantum-chemical methods using Gaussian 09.

Novel highly energetic components for rocket propellants based on polycyclic cage alkylnitramine compounds. Polynitro hexaazaisowurtzitanes with high performance and significantly lower sensitivity than CL-20.

The paper addresses to the study of the physicochemical properties of new high-energy substances: nitro derivatives of various kinds of nitrogenous heterocyclic nuclei. The enthalpy of formation of the molecules in the gas phase is obtained using quantum-chemical calculations (Gaussian 09). Various methods for solving the stationary Schrödinger equation are used: G4MP2, G4, CBS-4M, CBS-QB3, ω B97XD/aug-cc-pVTZ, B3LYP/6-311+G(2d,p), M062X/6-311+G(2d,p). The results of calculations obtained by the atomization method and the method of isogyric reactions are comparatively assessed. Various calculation methods are compared in terms of accuracy and time costs.

The relative efficacy of real energetic plasticizers and polymers for model solid composite propellants comprising 25% aluminum hydride, 50% dinitramide ammonium salt and 25% binder (20% a plasticizer and 5% a polymer) has been estimated. The quantitative dependence of the efficiency of plasticizers on the value of their enthalpy of formation ΔHt0, the oxygen coefficient α, percentage of hydrogen %H and density d has been revealed. 3,4-Dinitrofurazan tested as a plasticizer for the binder provides effective impulse values at the 3rd stage up to ∼2 s higher than those for other plasticizers.

Correction for ‘[(3-Nitro-1H-1,2,4-triazol-1-yl)-NNO-azoxy]furazans: energetic materials containing an N(O)N–N fragment’ by Dmitry A. Gulyaev et al., RSC Adv., 2021, 11, 24013–24021, DOI: 10.1039/D1RA03919A.

Novel energetic azoxy-and azofurazans bearing nitro-NNO-azoxy and amino groups were synthesized using the ammonolysis of some known (nitro-NNO-azoxy)furazans. 3-Amino-4-{[4'-(nitro-NNO-azoxy)furazan-3'-yl] -NNO-azoxy}furazan displays the highest melting point (114 degrees C, decomp.) among the known (nitro-NNO-azoxy)furazans, optimal density (1.80 g cm(-3)), high experimental enthalpy of formation (639 kcal kg(-1)) and mechanical sensitivity on the level of PETN. In terms of the specific impulse level, the model solid composite propellant formulations based on this compound outperform similar formulations based on RDX, HMX or CL-20 by 7-12 s.

Three novel energetic furazans with a cyano-NNO-azoxy group were synthesized using cyanamide and 2,2,2-trifluoro-N-(4-nitrosofurazan-3-yl)acetamide as the starting compounds. (Cyano-NNO-azoxy)furazans obtained display high experimental enthalpies of formation (+742 to +1073 kcal kg-1), good thermal stability (Tonset = 193-222 degrees C) and moderate mechanical sensitivity. These compounds may be of interest as energetic fillers in solid fuels for ramjet engines and in solid composite propellants.

The article presents high-performance calculations, using quantum chemical ab initio methods, of thermochemical characteristics of high-energy compounds: C2N6O4, C2N6O5, C2N6O6, C2H2N6O4, C3HN7O6, C3HN7O4F2, C4N10O12, C3HN6O4F, C4N10O8F4, C4N8O8F2. The IR absorption spectra, structural parameters and atomic displacements for the most intense vibrations, as well as the enthalpies of formation are provided in the article. The calculations were performed at the B3LYP/6-311+G(2d,p) level and using the combined methods CBS-4M and G4 within the Gaussian 09 application package (Linda paralellization). It is shown that the enthalpy of formation depends on the molecule structure.

A smooth synthesis of 4H-[1,2,3]triazolo[4,5-c][1,2,5]oxadiazole 5-oxide 1 and its energetic salts (ammonium, hydroxylammonium, guanidinium, triaminoguanidinium) is reported. The compounds synthesized were characterized by multinuclear nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy, mass spectrometry, elemental analysis, differential scanning calorimetry, single-crystal, and powder X-ray diffraction. All the compounds possess a beneficially high enthalpy of formation (88.9-168.0 kcal.mol(-1)). These data, in combination with the experimentally determined densities (1.702-1.934 g.cm(-1)), were used to calculate the detonation pressures (33.9-43.1 GPa) and velocities (8.86-9.31 km.s(-1)). The majority of the synthesized energetic salts had moderate impact and friction sensitivity, which made them promising candidates for various energy applications, including their use as components of solid composite propellants. It was shown that compounds 1 and 2c-f had higher energetic characteristics as components of solid composite propellants (the specific impulse was higher by 5-10 s) than HMX or CL-20 in propellant formulations.

The heat of combustion and enthalpy of formation of bis(4 ” -nitro[3,3 ' :4 ' ,3 ” ]terfurazan-4-yl)-diazene (DNFNF) and (bis(4 ” -azido-[3,3 ' :4 ' ,3 ” ]terfurazan-4-yl)-diazene (DAzFNF) were first experimentally determined. It is found that the energy increment for replacing the nitro group with an azide group in the furazan cycle averages 290 kJ/mol and is close to the increment for replacing NO 2 with N 3 in trinitroethane. The dependence of the energy parameters of metal-free rocket propellants based on a mixture of ammonium perchlorate and DNFNF or DAzFNF with an active binder on the content of the high-enthalpy component in the formulation was studied by thermodynamic analysis.