- Strategies toward the design of energetic ionic liquids: Nitro- and nitrile-substituted N,N′-dialkylimidazolium salts
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Twelve novel 1,3-dialkylimidazolium salts containing strongly electron-withdrawing nitro- and cyano-functionalities directly appended to the cationic heterocyclic rings have been synthesized; the influences of the substituents on both formation and thermal properties of the resultant ionic liquids have been determined by DSC, TGA, and single crystal X-ray diffraction, showing that an electron-withdrawing nitro-substituent can be successfully appended and has a similar influence on the melting behaviour as that of corresponding methyl group substitution. Synthesis of di-, or trinitro-substituted 1,3-dialkylimidazolium cations was unsuccessful due to the resistance of dinitro-substituted imidazoles to undergo either N-alkylation or protonation, while 1-alkyl-4,5-dicyanoimidazoles were successfully alkylated to obtain 1,3-dialkyl-4,5-dicyanoimidazolium salts. Five crystal structures (one of each cation type) show that, in the solid state, the NO2-group has little significant effect, beyond the steric contribution, on the crystal packing. the Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2006.
- Katritzky, Alan R.,Yang, Hongfang,Zhang, Dazhi,Kirichenko, Kostyantyn,Smiglak, Marcin,Holbrey, John D.,Reichert, W. Matthew,Rogers, Robin D.
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- 1-Alkylation of 4,5-dicyanoimidazole by ortho esters
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Reexamination of the reaction of ortho esters with diaminomaleonitrile (1) or 4,5-dicyanoimidazole (3a) revealed that 1-alkyl-4,5-dicyanoimidazoles 4a-f can be obtained in high yield in a one-pot procedure without any additional reagent. This simple procedure is economically competitive with other known methods. Several products previously reported for similar reactions have been shown to be the imidates of diaminomaleonitrile, 2b and 7.
- Johnson
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