Protic Ionic Liquids Can Be Both Free Proton Conductors and Benign Superacids

<div>Superacids have been the source of much spectacular chemistry, but very little interesting physics despite the fact that the states of cations formed by transfer of the superacid proton to molecular bases, can approach that of the cations in free space. Indeed some of the very strongest acids, such as HPF6 and HAlCl4, have no independent existence due to lack of screening of the bare proton self-energy: their acidities can only be assessed by study of the conjugate bases. Here we show that, by allowing the protons of transient HAlCl4 and HAlBr4 to relocate on pentafluoropyridine, PFP - a very weak base that is stable to superacids - we can create glassforming protic ionic liquids (PILs) which are themselves superacids but, being free of superacid vapors, are of benign character. At Tg, conductivities exceed “good” ionic liquid values by 9 decades, so must be superprotonic. Anomalous Walden plots confirm superprotonicity.</div>

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Protic Ionic Liquids Can Be Both Free Proton Conductors and Benign Superacids .

10.26434/chemrxiv.13249814 ◽

2020 ◽

Author(s):

younes ansari ◽

kazuhide ueno ◽

Austen Angell

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Free Space ◽

Proton Conductors ◽

Weak Base ◽

Protic Ionic Liquids ◽

Self Energy ◽

Conjugate Bases ◽

Molecular Bases ◽

Independent Existence

<div>Superacids have been the source of much spectacular chemistry, but very little interesting physics despite the fact that the states of cations formed by transfer of the superacid proton to molecular bases, can approach that of the cations in free space. Indeed some of the very strongest acids, such as HPF6 and HAlCl4, have no independent existence due to lack of screening of the bare proton self-energy: their acidities can only be assessed by study of the conjugate bases. Here we show that, by allowing the protons of transient HAlCl4 and HAlBr4 to relocate on pentafluoropyridine, PFP - a very weak base that is stable to superacids - we can create glassforming protic ionic liquids (PILs) which are themselves superacids but, being free of superacid vapors, are of benign character. At Tg, conductivities exceed “good” ionic liquid values by 9 decades, so must be superprotonic. Anomalous Walden plots confirm superprotonicity.</div>

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DFT Study on the Chemical Absorption Mechanism of CO2 in Diamino Protic Ionic Liquids

The Journal of Physical Chemistry B ◽

10.1021/acs.jpcb.0c08500 ◽

2021 ◽

Vol 125 (5) ◽

pp. 1416-1428

Author(s):

Jing Ma ◽

Yutong Wang ◽

Xueqing Yang ◽

Mingxuan Zhu ◽

Baohe Wang

Keyword(s):

Ionic Liquids ◽

Dft Study ◽

Protic Ionic Liquids ◽

Absorption Mechanism ◽

Chemical Absorption

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The Synthesis of Poly(Vinyl Alcohol) Grafted with Fluorinated Protic Ionic Liquids Containing Sulfo Functional Groups

Molecules ◽

10.3390/molecules26144158 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4158

Author(s):

Patrycja Glińska ◽

Andrzej Wolan ◽

Wojciech Kujawski ◽

Edyta Rynkowska ◽

Joanna Kujawa

Keyword(s):

Ionic Liquids ◽

Vinyl Alcohol ◽

Proton Exchange ◽

Polymer Materials ◽

Polymerization Reaction ◽

Poly Vinyl Alcohol ◽

Hydroxyl Groups ◽

Protic Ionic Liquids ◽

Synthesis Route ◽

Sulfo Groups

There has been an ongoing need to develop polymer materials with increased performance as proton exchange membranes (PEMs) for middle- and high-temperature fuel cells. Poly(vinyl alcohol) (PVA) is a highly hydrophilic and chemically stable polymer bearing hydroxyl groups, which can be further altered. Protic ionic liquids (proticILs) have been found to be an effective modifying polymer agent used as a proton carrier providing PEMs’ desirable proton conductivity at high temperatures and under anhydrous conditions. In this study, the novel synthesis route of PVA grafted with fluorinated protic ionic liquids bearing sulfo groups (–SO3H) was elaborated. The polymer functionalization with fluorinated proticILs was achieved by the following approaches: (i) the PVA acylation and subsequent reaction with fluorinated sultones and (ii) free-radical polymerization reaction of vinyl acetate derivatives modified with 1-methylimidazole and sultones. These modifications resulted in the PVA being chemically modified with ionic liquids of protic character. The successfully grafted PVA has been characterized using 1H, 19F, and 13C-NMR and FTIR-ATR. The presented synthesis route is a novel approach to PVA functionalization with imidazole-based fluorinated ionic liquids with sulfo groups.

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Development of a robust soft-SAFT model for protic ionic liquids using new high-pressure density data

Fluid Phase Equilibria ◽

10.1016/j.fluid.2021.113036 ◽

2021 ◽

pp. 113036

Author(s):

Emanuel A. Crespo ◽

Liliana P. Silva ◽

Cristina I.P. Correia ◽

Mónia A.R. Martins ◽

Ramesh L. Gardas ◽

...

Keyword(s):

High Pressure ◽

Ionic Liquids ◽

Protic Ionic Liquids ◽

Density Data

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Insights into the translational and rotational dynamics of cations and anions in protic ionic liquids by means of NMR fast-field-cycling relaxometry

Physical Chemistry Chemical Physics ◽

10.1039/d0cp05440b ◽

2021 ◽

Vol 23 (4) ◽

pp. 2663-2675

Author(s):

Viviane Overbeck ◽

Henning Schröder ◽

Anne-Marie Bonsa ◽

Klaus Neymeyr ◽

Ralf Ludwig

Keyword(s):

Ionic Liquids ◽

Rotational Dynamics ◽

Protic Ionic Liquids ◽

Field Cycling ◽

Fast Field ◽

Hydrogen Bonded

NMR Fast-Field-Cycling (FFC) relaxometry provides important information about translational and rotational dynamics of hydrogen bonded protic ionic liquids (PILs).

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