2534-66-9Relevant articles and documents
Physicochemical properties of hydrophobic ionic liquids containing 1-octylpyridinium, 1-octyl-2-methylpyridinium, or 1-octyl-4-methylpyridinium cations
Papaiconomou, Nicolas,Salminen, Justin,Lee, Jong-Min,Prausnitz, John M.
, p. 833 - 840 (2007)
This paper reports the synthesis of some ionic liquids containing cations 1-octylpyridinium [OPYR]+, 1-octyl-2-methylpyridinium [2MOPYR] +, or 1-octyl-4-metnylpyridinium [4MOPYR]+ and anions dicyanamide [N(CN)2]-, bis(trifluoromethylsulfonyl)imide [Tf2N]-, bis(pentafluoroethylsulfonyl)imide [BETI] -, trifluoromethyl sulfonate [TfO]-, nonafluorobutyl sulfonate [NfO]-, tetrafluoroborate [BF4]-, trifluorophenylborate [BF3PH]-, tetraphenylborate [BPh4] or hexafluoroarsenate [AsF6]-. Melting points, decomposition temperatures, densities, mutual solubilities with water, and viscosities have been measured. Unlike similar ionic liquids containing imidazolium cations, pyridinium ionic liquids studied here are nearly immiscible with water. Viscosities are similar, and water contents are slightly lower than those for ionic liquids containing imidazolium cations.
Micelle formation as a factor influencing the mode(s) of metal ion partitioning into: N -alkylpyridinium-based ionic liquids (ILs): Implications for the design of IL-based extraction systems
Wankowski, James L.,Kaul, Michael J.,Dietz, Mark L.
supporting information, p. 5674 - 5682 (2017/12/06)
Prior studies of metal ion partitioning between an acidic aqueous phase and an ionic liquid in the presence of a macrocyclic polyether have demonstrated that the overall partitioning is a composite of three distinct pathways: neutral complex/ion-pair extraction, exchange of a cationic metal-crown ether (CE) complex for the cationic constituent of the IL, and exchange of the metal ion for a hydronium ion in a CE-H3O+ complex formed during acid preconditioning of the IL. The obvious undesirability of the ion-exchange pathways, which can lead to substantial loss of the IL cation to the aqueous phase, has led to efforts to identify means by which these processes can be suppressed or eliminated. Prior work with N,N′-dialkylimidazolium and quaternary ammonium bis [(trifluoromethyl)sulfonyl]imides has shown that increasing the hydrophobicity of the IL cation can be an effective means of diminishing the contribution of ion-exchange. Work with the corresponding N-alkylpyridinium ILs, however, indicates that in certain instances, an increase in the hydrophobicity of the IL cation is accompanied by a marked increase in its propensity to self-associate, leading to the formation of micelles in the aqueous phase. The net effect is to diminish or even negate the expected beneficial effect of IL cation hydrophobicity in reducing the contribution of ion exchange to the overall metal ion partitioning process, adversely impacting the "greenness" of extraction processes employing these ILs.
Thermochemistry of the pyridinium- and pyrrolidinium-based ionic liquids
Verevkin, Sergey P.,Ralys, Ricardas V.,Emel'Yanenko, Vladimir N.,Zaitsau, Dzmitry H.,Schick, Christoph
, p. 353 - 358 (2013/06/04)
We applied DSC for the determination of enthalpies of synthesis reactions of pyridinium- and pyrrolidinium-based ionic liquids (ILs) from pyridine (or N-methyl-pyrrolidine) and n-alkyl bromides (with n = 4, 5, 6, 7, and 8). The combination of reaction enthalpy measurements by DSC with modern high-level first-principles calculations opens valuable indirect thermochemical options to obtain values of enthalpies of the formation and vaporization enthalpies of ILs.