Mono-N-oxidation of heterocycle-fused pyrimidines

2021 ◽  
Vol 50 (6) ◽  
pp. 2143-2148
Author(s):  
Yongxing Tang ◽  
Kejia Li ◽  
Ajay Kumar Chinnam ◽  
Richard J. Staples ◽  
Jean'ne M. Shreeve
Keyword(s):  
Mild Oxidation ◽  
Oxidation Reactions ◽  
Energetic Compounds ◽  
Thermal Stabilities

Mild oxidation reactions of nitrogen-rich heterocyclic rings lead to the formation of energetic compounds with the mono-N-oxide moiety which show good thermal stabilities and detonation performances.

scholarly journals 5-Nitrotetrazol and 1,2,4-Oxadiazole Methylene-Bridged Energetic Compounds: Synthesis, Crystal Structures and Performances

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7072
Author(s):  
Jiarong Zhang ◽  
Fuqiang Bi ◽  
Zhi Yang ◽  
Qi Xue ◽  
Bozhou Wang
Keyword(s):  
Structural Type ◽  
Energetic Compounds ◽  
X Ray Diffraction ◽  
Melting Points ◽  
Thermal Stabilities ◽  
X Ray ◽  
Apparent Activation Energies ◽  
The Impact ◽  
First Time ◽  
Impact Sensitivities

A new structural type for melt cast materials was designed by linking nitrotetrazole ring with 1,2,4-oxadiazole through a N-CH2-C bridge for the first time. Three N-CH2-C linkage bridged energetic compounds, including 3-((5-nitro-2H-tetrazol-2-yl) methyl)-1,2,4-oxadiazole (NTOM), 3-((5-nitro-2H-tetrazol-2-yl)methyl)-5-(trifluoromethyl)-1,2,4 -oxadiazole (NTOF) and 3-((5-nitro-2H-tetrazol-2-yl)methyl)-5-amine-1,2,4-oxadiazole (NTOA), were designed and synthesized through a two-step reaction by using 2-(5-nitro-2H-tetrazole -2-yl)acetonitrile as the starting material. The synthesized compounds were fully characterized by NMR (1H, 13C), IR spectroscopy and elemental analysis. The single crystals of NTOM, NTOF and NTOA were successfully obtained and investigated by single-crystal X-ray diffraction. The thermal stabilities of these compounds were evaluated by DSC-TG measurements, and their apparent activation energies were calculated by Kissinger and Ozawa methods. The crystal densities of the three compounds were between 1.66 g/cm3 (NTOA) and 1.87 g/cm3 (NTOF). The impact and friction sensitivities were measured by standard BAM fall-hammer techniques, and their detonation performances were computed using the EXPLO 5 (v. 6.04) program. The detonation velocities of the three compounds are between 7271 m/s (NTOF) and 7909 m/s (NTOM). The impact sensitivities are >40 J, and the friction sensitivities are >360 N. NTOM, NTOF and NTOA are thermally stable, with decomposition points > 240 °C. The melting points of NTOM and NTOF are 82.6 °C and 71.7 °C, respectively. Hence, they possess potential to be used as melt cast materials with good thermal stabilities and better detonation performances than TNT.

scholarly journals Molecular design and properties of bridged energetic pyridines derivatives

RSC Advances ◽  
2019 ◽  
Vol 9 (65) ◽  
pp. 37747-37758 ◽  
Author(s):  
Diandian Zhai ◽  
Jinpeng Wang ◽  
Lina Hao ◽  
Congming Ma ◽  
Peng Ma ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Electrostatic Potential ◽  
Electronic Structures ◽  
Molecular Design ◽  
Detonation Properties ◽  
Energetic Compounds ◽  
Thermal Stabilities

A series of bridged pyridine-based energetic compounds were designed and their geometrical/electronic structures, ΔHf, detonation properties, thermal stabilities, thermodynamic properties and electrostatic potential were fully investigated using DFT.

Study on the synthesis of 2-fluoro-2,2-dinitroethyl esters as a potential melt cast matrix in explosive charges

2017 ◽  
Vol 41 (21) ◽  
pp. 12700-12706 ◽  
Author(s):  
Jinchao Ma ◽  
Hongwei Yang ◽  
Guangbin Cheng
Keyword(s):  
Detonation Properties ◽  
Energetic Compounds ◽  
Melting Points ◽  
Thermal Stabilities ◽  
Explosive Charges

Polynitro energetic compounds with low melting points, high thermal stabilities, good detonation properties, and considerably mechanical insensitivities are reported; some of these compounds are promising potential replacements of TNT used in melt cast explosives.

Thermal stabilities, packing coefficients and molecular packings in a series of homologous liquid crystals

1979 ◽  
Vol 40 (3) ◽  
pp. 309-313 ◽  
Author(s):  
J. Shashidhara Prasad ◽  
P.K. Rajalakshmi
Keyword(s):  
Liquid Crystals ◽  
Thermal Stabilities

Mechanism of Oxidation Reactions of Bromine

1958 ◽  
Vol 14 (5_6) ◽  
pp. 357-360
Author(s):  
K. C. Grover ◽  
R. C. Mehrotra
Keyword(s):  
Oxidation Reactions ◽  
Mechanism Of Oxidation

Mechanism of Oxidation Reactions of Bromine

1958 ◽  
Vol 14 (5_6) ◽  
pp. 345-356 ◽  
Author(s):  
K. C. Grover ◽  
R. C. Mehrotra
Keyword(s):  
Oxidation Reactions ◽  
Mechanism Of Oxidation

Thermo-Oxidative Decomposition of Lovage (Levisticum officinale) and Davana (Artemisia pallens) Essential Oils under Simulated Tobacco Heating Product Conditions

2020 ◽  
Vol 29 (1) ◽  
pp. 27-43
Author(s):  
Emma Jakab ◽  
Zoltán Sebestyén ◽  
Bence Babinszki ◽  
Eszter Barta-Rajnai ◽  
Zsuzsanna Czégény ◽  
...  
Keyword(s):  
Low Temperature ◽  
Essential Oils ◽  
Relative Yield ◽  
Gas Chromatography Mass Spectrometry ◽  
Intramolecular Rearrangement ◽  
Oxidation Reactions ◽  
Pyrolysis Gas ◽  
Oxidative Decomposition ◽  
Oxidative Pyrolysis ◽  
Artemisia Pallens

SummaryThe thermo-oxidative decomposition of lovage (Levisticum officinale) and davana (Artemisia pallens) essential oils has been studied by pyrolysis-gas chromatography/mass spectrometry in 9% oxygen and 91% nitrogen atmosphere at 300 °C to simulate low-temperature tobacco heating conditions. Both lovage and davana oils contain numerous chemical substances; the main components of both oils are various oxygen-containing compounds. Isobenzofuranones are the most important constituents of lovage oil, and their relative intensity changed significantly during oxidative pyrolysis. (Z)-ligustilide underwent two kinds of decomposition reactions: an aromatization reaction resulting in the formation of butylidenephthalide and the scission of the lactone ring with the elimination of carbon dioxide or carbon monoxide. Davanone is the main component of davana oil, which did not decompose considerably during low-temperature oxidative pyrolysis. However, the relative yield of the second most intensive component, bicyclogermacrene, reduced markedly due to bond rearrangement reactions. Davana ether underwent oxidation reactions leading to the formation of various furanic compounds. The changes in the composition of both essential oils could be interpreted in terms of bond splitting, intramolecular rearrangement mechanisms and oxidation reactions of several constituents during low-temperature oxidative pyrolysis. The applied thermo-oxidative method was found to be suitable to study the stability of the essential oils and monitor the decomposition products under simulated tobacco heating conditions. In spite of the complicated composition of the essential oils, no evidence for interaction between the oil components was found. [Beitr. Tabakforsch. Int. 29 (2020) 27–43]

Oxidase Catalysis via an Aerobically Generated Dess-Martin Periodinane Analogue

2018 ◽  
Author(s):  
Asim Maity ◽  
Sung-Min Hyun ◽  
Alan Wortman ◽  
David Powers
Keyword(s):  
Chemical Synthesis ◽  
Aerobic Oxidation ◽  
Substrate Oxidation ◽  
Oxidation Catalysis ◽  
Hypervalent Iodine ◽  
Oxidation Reactions ◽  
Broad Array ◽  
Oxidation Chemistry ◽  
Reactive Oxidants

<p>Hypervalent iodine(V) reagents, such as Dess-Martin periodinane (DMP) and 2-iodoxybenzoic acid (IBX), are broadly useful oxidants in chemical synthesis. Development of strategies to access these reagents from O2 would immediately enable use of O2 as a terminal oxidant in a broad array of substrate oxidation reactions. Recently we disclosed the aerobic synthesis of I(III) reagents by intercepting reactive oxidants generated during aldehyde autoxidation. Here, we couple aerobic oxidation of iodobenzenes with disproportionation of the initially generated I(III) compounds to generate I(V) reagents. The aerobically generated I(V) reagents exhibit substrate oxidation chemistry analogous to that of DMP. Further, the developed aerobic generation of I(V) has enabled the first application of I(V) intermediates in aerobic oxidation catalysis.</p>

Operando Visualization of Morphological Dynamics in All-Solid-State Batteries

2019 ◽  
Author(s):  
Xiaohan Wu ◽  
Juliette Billaud ◽  
Iwan Jerjen ◽  
Federica Marone ◽  
Yuya Ishihara ◽  
...  
Keyword(s):  
Solid State ◽  
Solid Electrolytes ◽  
Rational Design ◽  
Morphological Evolution ◽  
Active Material ◽  
Composite Layer ◽  
Transference Number ◽  
Thermal Stabilities ◽  
Solid State Batteries ◽  
All Solid State Batteries

<div> <div> <div> <p>All-solid-state batteries are considered as attractive options for next-generation energy storage owing to the favourable properties (unit transference number and thermal stabilities) of solid electrolytes. However, there are also serious concerns about mechanical deformation of solid electrolytes leading to the degradation of the battery performance. Therefore, understanding the mechanism underlying the electro-mechanical properties in SSBs are essentially important. Here, we show three-dimensional and time-resolved measurements of an all-solid-state cell using synchrotron radiation x-ray tomographic microscopy. We could clearly observe the gradient of the electrochemical reaction and the morphological evolution in the composite layer. Volume expansion/compression of the active material (Sn) was strongly oriented along the thickness of the electrode. While this results in significant deformation (cracking) in the solid electrolyte region, we also find organized cracking patterns depending on the particle size and their arrangements. This study based on operando visualization therefore opens the door towards rational design of particles and electrode morphology for all-solid-state batteries. </p> </div> </div> </div>

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