Synthesis and Sorption Analysis of Task-specific Fluorous Ionic Liquids

Abstract

Six 1-alkyl-4-tridecafluorooctyl-1,2,4-triazolium triflimides 2a-f and 4-amino-1-tridecafluorooctyl-1,2,4-triazolium triflimide (4) were prepared from the respective iodides 1a-f (1a, 2a: n-propyl; 1b, 2b: n-butyl; 1c, 2c: n-hexyl; 1d, 2d: n-heptyl; 1e, 2e: n-octyl; 1f, 2f: n-decyl) and iodide 3 by ion metathesis. Compounds 2a and 4 are liquid at room temperature. Two liquid fluorous imidazolium salts bearing functionalized polar substituents were synthesized in an analogous manner, namely 1-(2-(diethylamino)ethyl)-3-(heptadecafluorodecyl)imidazolium triflimide (5b) and 1-(2-hydroxyethyl)-3-(heptadecafluorodecyl)imidazolium triflimide (6b) from the respective bromides 5a and 6a. The bis(triflimide) 5c has a melting point slightly above room temperature. Three fluorous ionic liquids (ILs; 2a, 5b, and 6b) were subjected to vapor sorption analysis at 25 • C and exhibited dual affinity to water and, even much more pronounced, to methoxynonafluorobutane (hydrofluoroether HFE-7100). Thus, IL 6b absorbed 3.2 % (by weight) water and 200 % HFE, whereas ILs 2a and 5b absorbed 0.4 and 0.5 % water, but 300 and 1200 % HFE, respectively. Commercial 1-butyl-2,3-dimethyl-imidazolium triflimide and 1-ethyl-3-methyl-imidazolium triflimide were used as reference compounds and absorbed 0.9 and 2.2 % water, respectively, but only 17 % HFE.

A Fluoroponytailed NHC–Silver Complex Formed from Vinylimidazolium/AgNO3 under Aqueous–Ammoniacal Conditions

“…Therefore, new technologies to deal with it are required [63,64]. In the case of hydrophobic fluoroponytailed azolium-based ionic liquids, which belong to the same family of potential F-NHC precursors, it is worth mentioning that not only the counter ions but also the side chains accompanying the polyfluoroalkyl residue exhibit strong and tunable effects on the mutual solubility towards binary and ternary phases with aqueous and hydrofluoroether systems [54].…”

Highly‐fluorinated Triaminocyclopropenium Ionic Liquids

“…Although the cationic moiety is typically imidazolium, [3,5,7,[9][10][11][12][13] examples with a cation such as pyridinium, [11,14,15] ammonium, [15,16] phosphonium [14,16] or triazolium are also known. [11,17] There is also a number of examples with longer spacer groups. [6,11,13,[18][19][20] Related to this class is the benzyl-functionalised imidazolium (IM) IL [BuIMCH 2 C 6 F 5 ]NTf 2 which contains a perfluorophenyl group.…”

“…The value of n varies greatly, but six is most common. Although the cationic moiety is typically imidazolium, [3,5,7,9–13] examples with a cation such as pyridinium, [11,14,15] ammonium, [15,16] phosphonium [14,16] or triazolium are also known [11,17] . There is also a number of examples with longer spacer groups [6,11,13,18–20] .…”