SYNTHESIS OF 2-NITRO-1,3-BIS(3,3’-DIHYDROXYMETHYL)-1,2,3-TRIAZOLYL-2-AZAPROPANE BY THE REACTION OF AZIDE-ALKYN CYCLOADDITION

2-Нитро-1,3-бис(3,3'-дигидроксиметил)-1,2,3-триазолил-2-азапропан (2-НДТАП) представляет интерес в качестве исходного вещества в синтезе высокоэнергетических соединений. В статье рассмотрен синтез 2-НДТАП реакцией азид-алкинового циклоприсоединения 1,3-диазидо-2-нитро-2-азапропана с пропаргиловым спиртом в среде трет-бутилового спирта в присутствии медного катализатора (проволока, порошок меди, оксид меди, нанооксид меди). Исследовано влияние катализатора и температуры процесса на его продолжительность, выход и качество продукта. Структура 2-НДТАП подтверждена методами ИК- и ЯМР-спектроскопии. В результате разработан метод получения 2-НДТАП с выходом 62 % и содержанием основного вещества выше 97 %. 2-Nitro-1,3-bis (3,3'-dihydroxymethyl)-1,2,3-triazolyl-2-azapropane (2-NDTAP) is of interest as a starting material in the synthesis of high-energy compounds. The article discusses the synthesis of 2-NDTAP the reaction of azide-alkyne cycloaddition 1,3-diazido-2-nitro-2-azapropane with propargyl alcohol in tert-butyl alcohol in the presence of a copper catalyst (wire, copper powder, copper oxide, nano copper oxide). The influence of the catalyst and the temperature of the process on its duration, yield and product quality has been investigated. The structure of 2-NDTAP was confirmed by IR and NMR spectroscopy. As a result, a method for obtaining 2-NDTAP with a yield of 62 % and a basic substance content of more than 97 % was developed.

Effect of Electric Current on SPS Densification of Spherical Copper Powder

When a current is involved, as in spark plasma sintering, metallic powders are heated by the Joule effect through both tool and specimen. Other mechanisms might occur, but it is difficult to separate the role of the temperature from the role of the current inside the sample as, in most cases, the two parameters are not controlled independently. In this paper, the consolidation and the densification of a pure copper powder were studied in three configurations for obtaining different electric current paths: (i) current flowing through both the powder and the die, (ii) current forced into the powder and (iii) no current allowed in the powder. Electrical conductivity measurements showed that even low-density samples displayed higher conductivities than graphite by several orders of magnitude. FEM simulations confirmed that these copper specimens were mainly heated by the graphite punches. No modification of the microstructure by the flow of current could be observed. However, the absence of current in the specimen led to a decrease in densification. No significant temperature difference was modeled between the configurations, suggesting that differences are not linked to a thermal cause but rather to a current effect.

Improving the shielding efficiency and weight reducing of the radio-absorbing coating by adding a matching layer

The spectra of complex permittivity of the composites consisting of rubber silicone compound and electroconductive fine-dispersed silver-coated copper powder were investigated. To enhance the effectiveness of the composite interaction with microwaves and reduction of its weight and dimensions characteristics two and three-layer constructions were produced. Matching layers were made of foam glass material with addition SiC and Fe3O4.

Crystal structure and Hirshfeld surface analysis of di-μ-chlorido-bis[(acetonitrile-κN)chlorido(ethyl 5-methyl-1H-pyrazole-3-carboxylate-κ2 N 2,O)copper(II)]

The title compound, [Cu2Cl4(C5H10N2O2)2(CH3CN)2] or [Cu2(μ2-Cl)2(CH3—Pz-COOCH2CH3)2Cl2(CH3CN)2], was synthesized using a one-pot reaction of copper powder, copper(II) chloride dihydrate and ethyl 5-methyl-1H-pyrazole-3-carboxylate (CH3—Pz-COOCH2CH3) in acetonitrile under ambient conditions. This complex consists of discrete binuclear molecules with a {Cu2(μ2-Cl)2} core, in which the Cu...Cu distance is 3.8002 (7) Å. The pyrazole-based ligands are bidentate coordinated, leading to the formation of two five-membered chelate rings. The coordination geometry of both copper atoms (ON2Cl3) can be described as distorted octahedral on account of the acetonitrile coordination. A Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H...H (40%), H...Cl/Cl...H (24.3%), H...O/O...H (11.8%), H...C/C...H (9.2%) and H...N/N...H (8.3%) interactions.