Relaxational Dynamics in the PYR14-IM14 Ionic Liquid by Mechanical Spectroscopy

Abstract

The anelastic spectrum of the N-butyl-N-methyl-pyrrolidinium (trifluoromethanesulfonyl) (nonafluorobutanesulfonyl)imide (PYR 14 -IM 14 ) is reported for the first time. On cooling, at 4 Kmin -1 the sample undergoes a glass transition around 190 K. In the liquid phase, a thermally activated relaxation process is measured and it is analyzed by means of a modified Debye model. The best fit results indicate that the peak is related to the ion hopping between non-equivalent configurations which are mainly defined by the anion conformer configuration.

Mechanical spectroscopy study of ionic liquids with quaternary cations: Effect of conformational flexibility

“…Indeed a correlation between high conformational flexibility and high ion mobility has been shown for several ions [8]. Moreover, it has been hypothesized that anion conformational relaxation correlates with translational diffusion [9][10][11][12].…”

“…Macroscopic properties are defined by microscopic properties and intermolecular interactions and, among various molecular features, a fundamental role is played by conformational flexibility [4][5][6][7][8][9][10][11][12]. In particular, the ions composing ILs usually present more than one conformer; in this case the ion has a high conformational flexibility when both the energy difference between the different configurations and the barrier between them is small compared to the available thermal energy [4].…”

Microscopic Structural and Dynamic Features in Triphilic Room Temperature Ionic Liquids

“…Such a scenario (Shen et al, 2012; Greaves et al, 2013; Pereiro et al, 2013b; Hettige et al, 2014; Brehm et al, 2015; Vieira et al, 2015; Ferreira et al, 2017; Shimizu et al, 2017) opens the way to simultaneous solvation of completely incompatible components into the homogeneous FIL, as each compound (e.g., a salt, an oil, and a fluorous compound) can be simultaneously dissolved into the same mesoscopically organized medium (Weiss et al, 2017; Tsurumaki and Ohno, 2018). In this contribution, we report on the structural properties of a series of 1-alkyl-3-methyimidazolium ([C n mim], where n indicates the number of carbon atoms along the side alkyl chain, with n = 2, 4, and 8) (trifluoromethanesulfonyl)(nonafluorobutylsulfonyl) imide ([IM 14 ], 1 and 4 represent the number of carbon atoms on the two sides of the imide anion) [see e.g., (Johansson et al, 2010; Montanino et al, 2012; Jeremias et al, 2013; Russina et al, 2013, 2017a; Castiglione et al, 2014; Paolone et al, 2018)], at ambient conditions. Scheme 1 represents the chemical structure of the probed FILs.…”

Imidazolium-based Ionic Liquids Impregnated in Silica and Alumina Supports for CO2 Capture

“…Ionic liquids (ILs) are a class of organic salts formed by combining organic cations and inorganic or organic anions resulting in compounds presenting melting temperature lower than 100°C 14,15 . ILs are candidates for replacing aqueous amine solution in CO 2 capture processes 15,16 due to their physico-chemical properties (like negligible vapor pressure) as well as CO 2 sorption capacity 1,[17][18][19][20] . Ionic liquids' properties depend on cation and anion size, shape and nature 21,22 .…”