Впервые синтезированы новые энергоемкие соединения 4,8-дицианометил-4H,8H-дифуразано[3,4-b:31,41-e]пиперазин (ДЦМФП) и 4,8-дитетразолометил-4H,8H-дифуразано[3,4-b:31,41-e]пиперазин (ДТМФП). Описан синтез этих соединений. Оба соединения исследованы как возможные диспергаторы твердых топлив для газогенерирующих двигателей, определены их плотности, энтальпии сгорания и образования, чувствительности к удару и трению (у ДЦМФП чувствительность очень низкая, на уровне тротила; у ДТМФП - на уровне октогена), оценена баллистическая эффективность твердых топлив на основе ДЦМФП и ДТМФП (у 7-амино-7Н-дифуразано[3,4-b:31,41-f]фуроксано[311,411-d]азепина, он же Az(O)NH2, первый выигрывает 4%, второй проигрывает ∼ 1,5%), проведено сравнение и с рядом других диспергаторов, разрабатываемых в течение последних нескольких лет. Методом дифференциального термического анализа (ДТА) в неизотермическом режиме проведено предварительное тестирование ДЦМФП и ДТМФП на термостойкость, показано, что эти компоненты весьма стабильны, так называемая температура начала интенсивного разложения составляет 312 и 270 ◦C соответственно.

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

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.

A solid trimolecular complex (TMC II) formed by molecules of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), H2O2, and H2O in a molar ratio of 2 : 0.8 : 0.2 and its crystal structure is studied. The parameters of the TMC II monoclinic cell at a temperature of 100 K are as follows: a = 28.4513(15) Å, b = 8.9636(6) Å, c = 12.7811(8) Å, β = 113.486(9)°, and V = 2989.5(3) Å3; and the calculated density is 2.023 g/cm3. Taking into account the real ratio of TMC components II, the density at 292 K is 1.959 g/cm3. The structure of TMC II contains CL-20 molecules in two conformational states, as a result of which the H2O2 molecules occur in different local environments. These results are confirmed by the data of chemical analysis, IR spectroscopy, and thermogravimetry (TG).

New bimolecular crystals (BMCs) of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) with tris[1,2,5]oxadiazolo[3,4-b:3´,4´-d:3″,4″-f]azepine-7-amine (AZ2) were synthesized. Four different crystal structures — two polymorphic modifications with the CL-20: AZ2 ratio of 1: 1 (BMCs 1 and 2) and two polymorphic modifications with the ratio of 1: 2 (BMCs 3 and 4) — were obtained depending on the crystallization conditions. These crystals were studied by X-ray diffraction. The results of quantum chemical calculations indicate that the new η-conformation found in crystal 1 is not a stable conformer of CL-20 and its existence is attributed to the crystal packing effects in structure 1.

При температурах 160–280°C изучен распад изоксазолинового кольца, образующегося при присоединении этилена к метил- и этилзамещенным бензонитрилоксидам. Реакция заключается в расщеплении изоксазолинового цикла на ацетальдегид и соответствующий ароматический нитрил. Скорость ее в расплаве и в инертных растворителях типа хлорбензола слабо зависит от строения ароматического заместителя, кинетические параметры имеют низкие значения: Е = (104 ± 8) кДж/моль и lg(А, c-1) = 7.2 ± 0.8. Только в том случае, когда бензольное кольцо содержит три этильных заместителя, разложение в расплаве идет быстрее, чем в растворе. Скорость циклораспада уменьшается при увеличении вязкости среды и увеличивается в растворителях, имеющих пониженную прочность связи C–H. Для соединений, полностью дейтерированных в изоксазолиновое кольцо, наблюдается обратный кинетический дейтериевый изотопный эффект. Полученные результаты объяснены в рамках бирадикального механизма раскрытия изоксазолинового цикла, включающего эффективную рекомбинацию бирадикала и его гибель в результате синхронной перегруппировки с выбросом ацетальдегида.

The decomposition of the isoxazole ring at 160–280°C formed by the addition of ethylene to methyland ethyl–substituted benzonitrile oxides is studied. The reaction consists in the cleavage of the isoxazole ring into acetaldehyde and the corresponding aromatic nitrile. Its rate in the melt and in inert solvents, such as chlorobenzene, only weakly depends on the structure of the aromatic substituent, with the kinetic parameters having low values: E = (104 ± 8) kJ/mol and log( A , s –1 ) = 7.2 ± 0.8. Only if the benzene ring has three ethyl substituents, the decomposition of the compound in the melt proceeds faster than in solution. The rate of the decomposition of the ring decreases with increasing viscosity of the medium, being higher in solvents with a lower strength of the C–H bond. For compounds with the fully deuterated isoxazole ring, the inverse kinetic H/D isotope effect is observed. The results are explained in terms of the biradical mechanism of the opening of the isoxazole ring that involves an effective recombination of the biradical and its loss through a synchronous rearrangement with acetaldehyde release.

The crystal structure of 3,3′-(2,4,6-triethyl-1,3-phenylene)bis(5-methyl-1,2,4-oxadiazole), which models the cross-linking fragment of polynitriles by benzodinitrile oxides, was determined by X-ray diffraction analysis. The kinetic regularities of its thermoinitiated oligomerization were studied by isothermal calorimetry and spectrophotometry. The process proceeds with self-acceleration, and the Arrhenius dependences of the initial and maximum reaction rates were determined. The reaction accelaration is determined by an increase in the viscosity of the reaction medium. Possible mechanisms were proposed for oligomerization.

The effect of the position and nature of substituents on the recyclization of substituted furoxans has been established.

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.

Structure of isoxazoline compounds formed via the reaction of alkyl-substituted benzonitrile oxides with ethylene was determined by X-ray diffraction method. Isoxazoline ring is flattened, the bond lengths in it depend slightly on the nature of substituents (CH 3 , C 2 H 5 ) and their position in the benzene ring and the angle of rotation relative to the isoxazoline ring. The connection N-O has a length 1.422 Å. Thermal decomposition of isoxazolines in a liquid phase (160–280°C) is accompanied by the release of acetaldehyde and aromatic nitrile. Both the structure of the cycle and its stability is practically independent of the structure of an aromatic substituent. The rate constant of the initial stage is characterized by the low significance of kinetic parameters, E = 104°8 kJ mol −1 and log a (A/ c ) = 7.2±0.8. The results obtained are rationalized in terms of biradical mechanism of isoxazoline ring-opening that includes an efficient recombination of the biradical and its disappearance as a result of synchronous multi-center rearrangement with the release of acetaldehyde.

We have studied destructive nitration of acetonyltriazole oxides and azotriazole oxides to the corresponding trinitromethyl derivatives.

The N-dealkylation of 2-alkyl or 2-benzyl-substituted 4,5-dinitro-1,2,3-triazole 1-oxides has been studied. Conditions have been found for N-de-tert-butylation and 4-amino-5-nitro-1,2,3-triazole 1-oxide has been synthesized for the first time.

Analysis of the 14N and 15N NMR spectroscopic data of 2-methyl-4,5-dinitro-1,2,3-triazole and of substituted 2-methyl-4(5)-nitro-1,2,3-triazole 1-oxides has shown the possibility of applying them for confirmation of the structures of the studied compounds.

A mass-spectrometric study of substituted 5- or 4-nitro-1,2,3-triazole 1-oxides showed the feasibility of using mass spectrometry for identifying 5-amino- and 5-alkylamino-2-methyl-4-nitro-1,2,3-triazole 1-oxides and their 4-amino-5-nitro isomers.

A hypothesis on the genetic determination of periodic fluctuations of the sensitivity to the mutagen thioTEPA in successive inbred generations of mice has been earlier put forward. This study was the initial stage of testing this hypothesis. The mouse strain CBA/LacY was divided into two substrains, which differed in the rate of generation change. As a result, two colonies of isogenic mice differing by 10-12 generations with respect to the inbred age were obtained. Both the rate and range of variations in the mutagen sensitivity (four generations per period of the cycle and 20-40% of cells with chromosome aberrations after the standard dose of 2.5 mg/kg of thioTEPA, respectively) in 19 generations of the "fast" substrain agreed with earlier data. The response of the "slow" substrain corresponded to the expected response of the "fast" substrain after the given number of generations. In the mice of generations F142 and F146 that lived simultaneously and differed in thioTEPA sensitivity, the effects of the carcinogen benzo[a]pyrene (BaP) were significantly different. The levels of these effects corresponded to the levels of the responses to thioTEPA. The data obtained agree with the hypothesis tested.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.