Thermodynamics of Imidazolium‐Based Ionic Liquids Containing the Trifluoromethanesulfonate Anion

Abstract

A thermochemical investigation of the series of 1‐alkyl‐3‐methylimidazolium ionic liquids (ILs) with the trifluromethanesulfonate CF3SO3− anion is presented. Absolute vapor pressures and vaporization enthalpies were measured by using a quartz crystal microbalance (QCM). The enthalpies of solutions were determined by solution calorimetry. Gas‐phase enthalpies of the formation of ILs were calculated by applying the high‐level quantum‐chemical method G3MP2. From a combination of experimental and theoretical results, the enthalpy of formation of aqueous CF3SO3− anion was derived for the first time.

Ultrathin ionic liquid films on metal surfaces: adsorption, growth, stability and exchange phenomena

“…[129] a: IL films prepared by PVD, if not indicated otherwise. 126 [92] 134(2) [88] 137(5) [92] 1280 [140] TPD; broad range for WL desorption. [92] Au ( 149(2) [88] 380 [140] TP-XPS; WL desorption shifts to < 370 K after replacement by [C 8 [140] TP-XPS; WL desorption shifts to < 420 K on 2H-TPPcovered Ag (111).…”

“…126 [92] 134(2) [88] 137(5) [92] 1280 [140] TPD; broad range for WL desorption. [92] Au ( 149(2) [88] 380 [140] TP-XPS; WL desorption shifts to < 370 K after replacement by [C 8 [140] TP-XPS; WL desorption shifts to < 420 K on 2H-TPPcovered Ag (111). [81][82][83] Au ( 157 [221] 162(3) [88] 12 [140] TPD; same temperature for multilayer and WL desorption.…”

“…[92] Au ( 149(2) [88] 380 [140] TP-XPS; WL desorption shifts to < 370 K after replacement by [C 8 [140] TP-XPS; WL desorption shifts to < 420 K on 2H-TPPcovered Ag (111). [81][82][83] Au ( 157 [221] 162(3) [88] 12 [140] TPD; same temperature for multilayer and WL desorption. [229,230] Cu ( (2) [212] 152(3) [212] 195 (19) [231] -Anions in contact with Cu surface decompose below 300 K. [75] a: Redhead analysis [232] with frequency factor…”

“…[C 8 C 1 Im][PF6 ] has a higher enthalpy of vaporization[88] and accordingly also a lower vapor pressure[140] than [C 8 C 1 Im][Tf 2 N]. For the WL on Ag(111), the lower desorption temperature of [C 8 C 1 Im][Tf 2 N] compared to [C 8 C 1 Im][PF 6] indicates a stronger adsorption of the latter on the metal surface that likely results from the smaller size of the [PF 6 ] − anion and thus a more localized charge which might induce a stronger image dipole within the metal.…”

Inhibiting Effect of Ionic Liquids on the Corrosion of Mild Steel in H2S and HCl Solution

“…However, some corrosion inhibitors have various defects in toxicity, solubility, and thermal stability [14]. Ionic liquids (ILs) have been identified as green solvents with low melting point, negligible vapor pressure, excellent thermal stability, and high solubility [15][16][17]. Therefore, ILs received extensive attention as green corrosion inhibitors [18][19][20][21].…”