- Synthesis of N-cyanoalkyl-functionalized imidazolium nitrate and dicyanamide ionic liquids with a comparison of their thermal properties for energetic applications
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The synthesis of 10 N-alkyl-N-cyanoalkyl-functionalized imidazolium (N-methyl- and N-butyl-N-((CH2)nCN)imidazolium; n = 1-4) nitrate and 11 N-alkyl-N-cyanoalkyl-functionalized imidazolium (N-methyl-N-((CH2)nCN)imidazolium; n = 1-6, N-(2-cyanoethyl)-N-((CH2)nCN)imidazolium; n = 1,3-6) dicyanamide salts was achieved via N-alkylation of substituted imidazoles with commercially available haloalkylnitriles followed by anion exchange. Based on their observed melting points, all dicyanamide salts and all but one nitrate salt (1-cyanomethyl-3-methylimidazolium nitrate) had melting points 100 °C, as did 13 of the 17 halide precursors also reported here. Differential scanning calorimetry data indicated that melting points decreased by increasing the N-alkyl or N-cyanoalkyl chain length or by exchanging with the dicyanamide anion, which produced the lowest melting points in comparison to analogous halide or nitrate salts. Thermogravimetric analyses indicated that thermal stability increased for longer N-cyanoalkyl substituent lengths and decreased significantly for nitrates and more so for dicyanamides bearing short-chain N-cyanoalkyl substituents (e.g., N-cyanomethyl, N-(1-cyanoethyl), and N-(2-cyanoethyl)) in comparison to halide precursors. Furthermore, for many of the N-cyanoalkyl-substituted salts (especially the dicyanamides), there was a significant production of thermally-stable char - presumably due to by-products formed from the reaction of either N-cyanoalkyl substituents, dicyanamide anion, or both, which resulted in thermally-stable polymers or cycles.
- Drab, David M.,Smiglak, Marcin,Shamshina, Julia L.,Kelley, Steven P.,Schneider, Stefan,Hawkins, Tommy W.,Rogers, Robin D.
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- A general design platform for ionic liquid ions based on bridged multi-heterocycles with flexible symmetry and charge
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A conceptual design platform for new ionic liquids with variable heterocycles, bridges, symmetry, and charge was developed using simple alkylation, click, and ionic liquid chemistries and demonstrated with 1-(2-(5-tetrazolidyl)ethyl)-3-(5-1H-tetrazolyl)methylimidazolium and its conversion into room-temperature ionic liquids as cation or as anion.
- Drab, David M.,Shamshina, Julia L.,Smiglak, Marcin,Hines, C. Corey,Cordes, David B.,Rogers, Robin D.
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- Domino reaction of N-(cyanomethyl)-1,3-azolium quaternary salts with o-hydroxybenzaldehydes: Scope and limitations
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A route towards chromenes, annulated with an imidazo[5,1-c][1,4]thiazine core through a base-promoted domino reaction of thiazolium quaternary salts, has been developed. The synthesised compounds show high cytotoxic activity against human tumour cell line
- Voskressensky,Festa,Storozhenko,Le,Nguyen,Varlamov
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- The selective oxidation of hydrocarbons on isolated iron active sites under ambient conditions
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The N-doped carbon material supported Fe catalysts were developed for the oxidation of C-H bond of hydrocarbons to ketones and alcohols. The supported Fe catalysts were prepared by pyrolysis of [CMIM]3Fe(CN)6 ionic liquid in activated carbon. And the Fe(Ⅲ)?CN-600 showed good activity and high selectivity for the oxidation of alfa C-H bond of alkylbenzenes. The isolated Fe(Ⅲ) iron active sites should be responsible for the high activity and selectivity for the oxidation of hydrocarbons to ketones. Several ketones were obtained in good to excellent yields. Moreover, cyclohexanone can also be obtained through the oxidation of cyclohexane.
- Qi, Zhengliang,Liu, Junmei,Guo, Wanwan,Huang, Jun
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p. 946 - 955
(2020/01/08)
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- General Reductive Amination of Aldehydes and Ketones with Amines and Nitroaromatics under H2 by Recyclable Iridium Catalysts
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Heterogeneous iridium catalysts were prepared and applied for the reductive amination of aldehydes and ketones with nitroaromatics and amines using H2. The iridium catalysts were prepared by pyrolysis of ionic liquid 1-methyl-3-cyanomethylimidazoulium chloride ([MCNI]Cl) with iridium chloride (IrCl3) in activated carbons. Iridium particles were well dispersed and stable in the N-doped carbon materials from [MCNI]Cl with activated carbon. The Ir@NC(600-2h) catalyst was found to be highly active and selective for the reductive amination of aldehydes and ketones using H2 and a variety of nitrobenzenes and amines were selectively converted into the corresponding secondary and tertiary amines. The Ir@NC(600-2h) catalyst can be reusable several times without evident deactivation.
- Sui, Dejun,Mao, Fei,Fan, Haipeng,Qi, Zhengliang,Huang, Jun
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supporting information
p. 1371 - 137
(2017/10/05)
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- Ionic liquids as precursors for efficient mesoporous iron-nitrogen-doped oxygen reduction electrocatalysts
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A ferrocene-based ionic liquid (Fe-IL) is used as a metal-containing feedstock with a nitrogen-enriched ionic liquid (N-IL) as a compatible nitrogen content modulator to prepare a novel type of non-precious-metal-nitrogen-carbon (M-N-C) catalysts, which feature ordered mesoporous structure consisting of uniform iron oxide nanoparticles embedded into N-enriched carbons. The catalyst Fesup10/sup@NOMC exhibits comparable catalytic activity but superior long-term stability to 20 wt% Pt/C for ORR with four-electron transfer pathway under alkaline conditions. Such outstanding catalytic performance is ascribed to the populated Fe (Feinf3/infOinf4/inf) and N (N2) active sites with synergetic chemical coupling as well as the ordered mesoporous structure and high surface area endowed by both the versatile precursors and the synthetic strategy, which also open new avenues for the development of M-N-C catalytic materials.
- Li, Zelong,Li, Guanglan,Jiang, Luhua,Li, Jinlei,Sun, Gongquan,Xia, Chungu,Li, Fuwei
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supporting information
p. 1494 - 1498
(2015/01/30)
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- IONIC LIQUIDS BASED ON IMIDAZOLIUM SALTS INCORPORATING A NITRILE FUNCTIONALITY
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Novel chemical compounds of the general formula K+A-, in which K+ is a 5- or 6- membered heterocyclic ring having 1-3 hetereo atoms, which can be independently N, S, or 0; with the proviso that at least one of the hetereo atoms must be a quaternized nitrogen atom having a -R'CN substituent, wherein R' is alkyl (C1 to C12); the heterocyclic ring having up to 4 or 5 substituents independently chosen from the moieties: (i) H; (ii) halogen or (iii) alkyl (C1 to C12) , which is unsubstituted or partially or fully substituted by further groups, preferably F, Cl, N(CnF(2n+1-x)Hx)2, O(CnF(2n+1-x)Hx), S02(CnF(2n+1-x)Hx)2 or CnF(2n+1-x)Hx where 1nF(2n+1-x.)Hx.)2, O(CnF(2n+1-x)Hx), S02(CnF(2n+1-x)Hx)2 or CnF(2n+1-x)Hx where 1- is any anion that provides a salt with a low melting point, below about 100 °C; A- can be halide, BF4- , PF6-, N03-, CH3CO2-, CF3SO3-, (CF3SO2)2N-, (CF3SO2)3C- CF3CO2- or N(CN)2- or [BF3RCN]-. These compounds can be used as industrial solvents, especially as ligands for efficient catalyst recycling.
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Page/Page column 10
(2008/06/13)
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