In Search of Ionic Liquids Incorporating Azolate Anions

Abstract

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.<100 degrees C) were obtained with all combinations of the 1-butyl-3-methylimidazolium cation ([C(4)mim](+)) and the heterocyclic azolate anions studied, and with several combinations of tetraethyl or tetrabutylammonium cations and the azolate anions. The [C(4)mim](+) azolates were liquid at room temperature exhibiting large liquid ranges and forming glasses on cooling with glass-transition temperatures in the range of -53 to -82 degrees C (except for the 3,5-dinitro-1,2,4-triazolate salt with m.p. 33 degrees 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.

Ionic Liquids Based on Azolate Anions

“…Consistent with previous observations, [62] salts of cation 6, in particular [1-Bu-3-Me-im][5-NO 2 -benztri] 6 a and [1-Bu-3-Me-im][5-NO 2 -benzim] 6 b, exhibited the lowest glass transition temperatures of À41 and À34 8C, respectively. As expected, the freezing and melting transitions were suppressed, due to the lower symmetry, charge diffuse, [1-Bu-3-Me-im] cation.…”

Investigation of the Stability of Quaternary Ammonium Methyl Carbonates

“…A decomposition temperature for TBQ MC of 180°C is also in general agreement with 206°C for TBQ Br derived by Chidambaram et al [23] from DSC measurements. Katritzky and coworkers [24] observed decomposition temperatures for a series of TBQ salts in the range of 180-222°C, also measured by DSC.…”

Study on Crystal Structure and Thermal Behavior of Sodium Tetrazolate and Sodium 5-Chlorotetrazolate

“…Thus, tetrazole derivative is an ideal high energy density materials (HEDMs) [1,2] . Besides, its chemical property is very active, a great varieties of derivatives can be obtained by deprotonation, protonation, substitution, corrdination reactions [3][4][5][6][7][8][9][10][11] which are widely used in biomedicine, agriculture, energetic materials, gas generating agent and microelectronics fields.…”