- In search of ionic liquids incorporating azolate anions
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Twenty-eight novel salts with tetramethyl-, tetraethyl-, and tetrabutylammonium and 1-butyl-3-methylimidazolium cations paired with 3,5-dinitro-1,2,4-triazolate, 4-nitro-1,2,3-triazolate, 2,4-dinitroimidazolate, 4,5-dinitroimidazolate, 4,5-dicyanoimidazolate, 4-nitroimidazolate, and tetrazolate anions have been prepared and characterized by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and single-crystal X-ray crystallography. The effects of cation and anion type and structure on the physicochemical properties of the resulting salts, including several ionic liquids, have been examined and discussed. Ionic liquids (defined as having m.p. 4mim]+) and the heterocyclic azolate anions studied, and with several combinations of tet raethyl or tetrabutylammonium cations and the azolate anions. The [C4mim] + azolates were liquid at room temperature exhibiting large liquid ranges and forming glasses on cooling with glasstransition temperatures in the range of -53 to -82°C (except for the 3,5-dinitro-1,2,4-triazolate salt with m.p. 33°C). Six crystal structures of the corresponding tetraalkylammonium salts were determined and the effects of changes to the cations and anions on the packing of the structure have been investigated.
- Katritzky, Alan R.,Singh, Shailendra,Kirichenko, Kostyantyn,Smiglak, Marcin,Holbrey, John D.,Reichert, W. Matthew,Spear, Scott K.,Rogers, Robin D.
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- Design and Synthesis of Energetic Materials towards Versatile Applications by N-trinitromethyl and N-nitromethyl Functionalization of Nitroimidazoles
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Modifying the properties of energetic materials is important not only for gaining insight into the relationship between structures and properties but also for multiple applications. A new family of energetic compounds, polynitroimidazoles featuring trinitromethyl, nitromethyl and methyl acetate moieties at the nitrogen position of heterocyclic rings were synthesized. The high-energy oxidizers 2-nitro and 4-nitro-1-(trinitromethyl)-1H-imidazoles were obtained by nitration of 1-acetonylpolynitroimidazoles in fuming HNO3 and concentrated H2SO4. 4,5-Dinitro-1-(nitromethyl)-1H-imidazole and 4,5-dinitro-1-(acetate methyl)-1H-imidazole were afforded by using 68 % HNO3 and concentrated H2SO4 through controllable synthesis. All the intermediates and the target compounds were confirmed by X-ray diffraction. It is noteworthy that one of the N-trinitromethyl nitroimidazole derivatives showed high density (ρ: 1.88 g cm?3), attractive positive oxygen balance (Ω: +18.3 %) and good detonation performance (D: 9003 m s?1) exceeding those of ADN, while N-nitromethyl derivative behaved higher thermal stability and lower sensitivity in contrast to those of NG. N-acetate methyl derivative gave an interesting melt-castable property (Tm.p.: 86 oC, Td: 224 oC), acceptable detonation performance as well as low sensitivity towards impact and friction (IS>40 J, FS>360 N), making it a competitive replacement for DNAN. These chemical and physical properties indicate that these novel materials show promising energetic performance towards future applications.
- Yin, Xin,Li, Jie,Zhang, Guojie,Zhang, Zhenqi,Ma, Qing,Wang, Jun,Wang, Shumin
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- Synthesis, thermal hazard analysis and density functional theory study of nitroimidazoles
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To understand the thermal decomposition mechanism and performance of nitroimidazoles, 1,4-dinitroimidazole (1,4-DNI), 2,4-dinitroimidazole (2,4-DNI) and 4,5-dinitroimidazole (4,5-DNI) were synthesized by 4-nitroimidazole firstly and all of them were studied using Differential Scanning Calorimetry (DSC), Accelerating Rate Calorimetry (ARC) and Density Functional Theory (DFT). The experiments show that among the four nitroimidazoles, the decomposition temperature and apparent activation energy of 1,4-DNI are relatively low. Theoretical calculations show that compared with C[sbnd]NO2, N[sbnd]NO2 is easier to break from the imidazole ring, and the detonation performance of 1,4-DNI is the best among the four nitroimidazoles. Dinitroimidazoles all contain two nitro groups, resulting in their sensitivity and energy much greater than 4-NI. Since 1,4-DNI is the only substance containing N[sbnd]NO2, the chemical activity of 1,4-DNI is further improved. In addition, 1,4-DNI has relatively excellent detonation performance, which can be used as the research direction of new energetic materials.
- Hao, Lina,Jiang, Juncheng,Liu, Xuqin,Ma, Congming,Ma, Peng,Pan, Yong,Xu, Xiaosong,Zhang, Renfa
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- Synthesis, anti-HIV-1 and antiproliferative evaluation of novel 4-nitroimidazole derivatives combined with 5-hydroxy-4-pyridinone moiety
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In an effort to synthesize more effective non-nucleoside reverse transcriptase inhibitors (NNRTIs) against the HIV-1 infection, a new series of novel 4-nitroimidazole derivatives combined with 5-hydroxy-4-pyridinone moiety were designed by molecular docking studies, prepared and characterized by spectroscopic techniques. All the synthesized compounds were in vitro evaluated for their inhibitory effect against the HIV-1 replication in the MT-4 cells. Results showed that none of these synthesized compounds displayed any specific anti HIV-1 activity. Surprisingly, these compounds showed high cytotoxicity against MT-4 cells with low selectivity index (50 = 1.3 μM and EC50 = 1.8 μM respectively).
- Shirvani, Pouria,Fassihi, Afshin,Saghaie, Lotfollah,Van Belle, Siska,Debyser, Zeger,Christ, Frauke
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- Method for preparing 4, 5-dinitroimidazole by adopting microchannel reactor
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The invention discloses a method for preparing 4, 5-dinitroimidazole by adopting a microchannel reactor. According to the method, raw material mixing is enhanced by using a micromixer, and the mixinguniformity is limited by uneven flow fields generated by stirring in a prior reactor; a flow focusing technology adopted by the HPIMM micromixer can force two fluid thin layers to flow through a convergence chamber so as to generate efficient and uniform thin layer contact reaction, and the stoichiometric ratio of reactants is precisely controlled, so that the consumption of strong acid is reducedfrom the source, and the generation of multi-nitration byproducts caused by acid amount and temperature change during the reaction in a prior kettle reactor is eliminated, mass transfer resistance iseliminated, generation of hot spots is avoided, and the problem that the 4, 5-dinitroimidazole has great safety problems caused by intense heat release in the prior reactor is solved. According to the invention, a microsystem is utilized to carry out the synthesis of 4-nitroimidazole and 4, 5-dinitroimidazole, the yields can reach to 96.1% and 92.4%.
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Page/Page column 0058-0069; 0073-0075; 0078-0079
(2019/06/27)
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- Synthesis, single crystal structure and performance of N-substituted derivatives of dinitroimidazole
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The N-substituted derivatives of dinitroimidazoles have been synthesized for application as energetic materials. The synthesized compounds were fully characterized by 1H 13C NMR spectroscopy and elemental analysis. Most of them were determined by single crystal X-ray diffraction. The calculated densities of the compounds range between 1.89 and 1.91 g cm -3 and the experimental densities between 1.75 and 1.84 g cm -3, as obtained by X-ray crystallographic analysis. Notably, densities of the N-substituted derivatives of dinitroimidazoles are increased when two amino groups are introduced but decreased when one amino group is introduced.
- Hou, Kehui,Ma, Congming,Liu, Zuliang
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p. 2837 - 2844
(2013/09/12)
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- Ionic liquids based on azolate anions
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Compartmentalized molecular level design of new energetic materials based on energetic azolate anions allows for the examination of the effects of both cation and anion on the physiochemical properties of ionic liquids. Thirty one novel salts were synthesized by pairing diverse cations (tetraphenylphosphonium, ethyltriphenylphosphonium, /V-phenyl pyridinium, 1butyl-3-methylimidazolium, tetramethyl-, tetraethyl-, and tetrabutylammonium) with azolate anions (5-nitrobenzimidazolate, 5-nitrobenzotriazolate, 3,5-dinitro-1,2,4-triazolate, 2,4-dinitroimidazolate, 4-nitro-l ,2,3-triazolate, 4,5-dinitroimidazolate, 4,5-dicyanoimidazolate, 4-nitroimidazolate, and tetrazolate). These salts have been characterized by DSC, TGA, and single crystal X-ray crystallography. The azolates in general are surprisingly stable in the systems explored. Ionic liquids were obtained with all combinations of the l-butyl-3-methylimidazoli-um cation and the heterocyclic azolate anions studied, and with several combinations of tetraethyl- or tetrabutylammonium cations and the azolate anions. Favorable structure-property relationships were most often achieved when changing from 4- and 4,5-disubstituted anions to 3,5- and 2,4-disubstituted anions. The most promising anion for use in energetic ionic liquids of those studied here, was 3,5-dinitro-l ,2,4-triazolate, based on its contributions to the entire set of target properties.
- Smiglak, Marcin,Corey Hines,Singh, Shailendra,Wilsion, Timothy B.,Vincek, Adam S.,Kirichenko, Kostyantyn,Katritzky, Alan R.,Rogers, Robin D.
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experimental part
p. 1572 - 1584
(2010/06/11)
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- Synthesis of 2,3-dihydro-7-nitroimidazo[5,1-b]oxazoles as potential tuberculostatic agents
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A series of 2,3-dihydro-7-nitroimidazo[5,1-b]oxazoles has been prepared in one-pot reaction. The proposed new method of their synthesis requires a treatment of 4,5-dinitroimidazole or 2-methyl-4,5-dinitroimidazole with oxiranes. Some of the obtained compounds have been tested in vitro for antimycobacterial activity and the spatial structure of them has been also discussed.
- Zwawiak, Justyna,Olender, Dorota,Zwolska, Zofia,Augustynowicz-Kopec, Ewa,Zaprutko, Lucjusz
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scheme or table
p. 229 - 233
(2009/04/04)
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- 1,4-Dinitroimidazole and Derivatives. Structure and Thermal Rearrangement
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Nitration of 4-nitroimidazole in acetic anhydride/glacial acetic acid gives 1,4-dinitroimidazole.The crystal and molecular structure of this compound have been determined by direct methods.Crystals are orthorombic; P212121, a 5.853(3), b 9.591(8), c 10.392(5) Angstroem, V 583.4(7) Angstroem3, Dm 1.76 g cm-1, Dc 1.80 g cm-1 (Z = 4); λ 0.71069 Angstroem; T 173 K.The structure was refined to R = 0.048 for 926 reflections 2?(I)>.Both 2-methyl-2-nitro- and 5-methyl-4-nitroimidazoles N-nitrate under the same conditions.When heated in solution at 100 -140 deg C 1,4-dinitro- and 2-methyl-1,4-dinitro-imidazoles rearrange to give C-nitro isomers and some denitration products, but 5(4)-methyl-1,4(5)-dinitroimidazole failed to give identifiable products.
- Grimmett, M. Ross,Hua, Sio-Tiok,Chang, Kuei-Choo,Foley, Sandra A.,Simpson, Jim
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p. 1281 - 1289
(2007/10/02)
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- Azoles. 27. Nitroimidazole derivatives, their antibacterial and fungicidal activity and electron affinity
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Nitroimidazole derivatives 3a-3g, 4a-4g and 5-8 were synthesized by treating 4,5-dinitro- and 2-methyl-4,5-dinitroimidazole (1,2) with phenacyl bromide, its p-substituted derivatives or epichlorohydrin. 1-(3-Chloro-2-hydroxypropyl)-4,5-dinitroimidazole (5) and its 2-methyl derivative 6 have been converted to imidazo-oxazoles 7 and 8 or amino imidazole derivatives 9-14 by the action of potassium carbonate or cyclic amines (pyrrolidine, piperidine, morpholine and N-methylpiperazine). Some of the newly synthesized nitroimidazole derivatives show antibacterial and fungicidal activity. The electron affinity of the nitroimidazole derivatives 1-24 is discussed on the basis of their half-wave potentials and in the connection with their eventual radiosensitizing properties.
- Zaprutko,Gajdzinski,Michalska,Pietkiewicz,Lutomski,Lukaszewski,Wrzeciono
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p. 817 - 820
(2007/10/02)
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