Bronsted Acidity in Ionic Liquids

Quaternary phosphine type hypercrosslinked polymer catalysts were successfully fabricated with the Friedel-Crafts alkylation reactions, benefit from synergistic effect between the Brönsted acidity of the hydroxyl group and nucleophilic of the...

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Physicochemical properties, Brönsted acidity and ecotoxicity of imidazolium-based organic salts: Non-toxic variants of protic ionic liquids

Journal of Molecular Liquids ◽

10.1016/j.molliq.2018.08.017 ◽

2018 ◽

Vol 269 ◽

pp. 178-186 ◽

Cited By ~ 7

Author(s):

Sabahat Sardar ◽

Cecilia Devi Wilfred ◽

Asad Mumtaz ◽

Jean-Marc Leveque ◽

Amir Sada Khan ◽

...

Keyword(s):

Ionic Liquids ◽

Physicochemical Properties ◽

Brønsted Acidity ◽

Protic Ionic Liquids ◽

Organic Salts ◽

Brönsted Acidity

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Spectroscopic determination of relative Brønsted acidity as a predictor of reactivity in aprotic ionic liquids

Chemical Communications ◽

10.1039/c5cc01226k ◽

2015 ◽

Vol 51 (30) ◽

pp. 6651-6654 ◽

Cited By ~ 2

Author(s):

Ariel I. Horowitz ◽

Paola Arias ◽

Matthew J. Panzer

Keyword(s):

Ionic Liquids ◽

Reaction Rates ◽

Spectroscopic Determination ◽

Bronsted Acids ◽

Brønsted Acidity ◽

Brönsted Acidity ◽

Relative Acidity

FTIR-enabled titration of pyridine with Brønsted acids in aprotic ionic liquids successfully predicts relative acidity and reaction rates.

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Brønsted Acidity and the Medium: Fundamentals with a Focus on Ionic Liquids

ChemPhysChem ◽

10.1002/cphc.201100087 ◽

2011 ◽

Vol 12 (9) ◽

pp. 1622-1632 ◽

Cited By ~ 44

Author(s):

Lynn M. Mihichuk ◽

Gordon W. Driver ◽

Keith E. Johnson

Keyword(s):

Ionic Liquids ◽

Brønsted Acidity ◽

Brönsted Acidity

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Synthesis and Properties of Magnetic Aryl-Imidazolium Ionic Liquids with Dual Brønsted/Lewis Acidity

Materials ◽

10.3390/ma11122539 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2539 ◽

Cited By ~ 4

Author(s):

Jui-Cheng Chang ◽

Che-Hsuan Yang ◽

I-Wen Sun ◽

Wen-Yueh Ho ◽

Tzi-Yi Wu

Keyword(s):

Ionic Liquids ◽

Lewis Acidity ◽

Brønsted Acidity ◽

Good Thermal Stability ◽

Magnetic Ionic Liquids ◽

Good Solubility ◽

Brönsted Acidity ◽

Lewis Acidic Sites ◽

Acidic Sites ◽

Electron Withdrawing Group

A series of unique tunable aryl-imidazolium magnetic ionic liquids (MILs) with dual acidity that contain both Brønsted and Lewis acidic sites (abbreviated as B-L MILs) were synthesized and characterized using nuclear magnetic resonance and mass spectrometry. Physical properties, such as thermal properties, magnetic susceptibility, and Brønsted and Lewis acidity, were measured. These properties were found to depend on the cation structure. These B-L MILs had good solubility in many organic solvents, good thermal stability, and low melting points, and exhibited magnet-like behavior. For these B-L MILs, the Brønsted acidity was measured using ultraviolet-visible (UV-Vis), and the Lewis acidity was measured using Fourier transform infrared spectroscopy (FTIR). The results showed that B-L MILs with an electron-withdrawing group in the aryl-imidazolium moiety had higher Brønsted acidity, whereas those with an electron-donating group had higher Lewis acidity. This type of ionic liquid, with both Brønsted and Lewis acidic sites, is expected to be a useful solvent and catalyst for organic reactions.

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The Proton Dissociation of Bio-Protic Ionic Liquids: [AAE]X Amino Acid Ionic Liquids

Molecules ◽

10.3390/molecules26010062 ◽

2020 ◽

Vol 26 (1) ◽

pp. 62

Author(s):

Ting He ◽

Cheng-Bin Hong ◽

Peng-Chong Jiao ◽

Heng Xiang ◽

Yan Zhang ◽

...

Keyword(s):

Ionic Liquids ◽

Amino Acid ◽

Acid Ester ◽

Amino Acid Ester ◽

Acidity Function ◽

Brønsted Acidity ◽

Protic Ionic Liquids ◽

Indicator Method ◽

Pka Values ◽

Brönsted Acidity

[AAE]X composed of amino acid ester cations is a sort of typically “bio-based” protic ionic liquids (PILs). They possess potential Brønsted acidity due to the active hydrogens on their cations. The Brønsted acidity of [AAE]X PILs in green solvents (water and ethanol) at room temperature was systematically studied. Various frameworks of amino acid ester cations and four anions were investigated in this work from the viewpoint of structure–property relationship. Four different ways were used to study the acidity. Acid dissociation constants (pKa) of [AAE]X determined by the OIM (overlapping indicator method) were from 7.10 to 7.73 in water and from 8.54 to 9.05 in ethanol. The pKa values determined by the PTM (potential titration method) were from 7.12 to 7.82 in water. Their Hammett acidity function (H0) values (0.05 mol·L−1) were about 4.6 in water. In addition, the pKa values obtained by the DFT (proton-transfer reactions) were from 7.11 to 7.83 in water and from 8.54 to 9.34 in ethanol, respectively. The data revealed that the cationic structures of [AAE]X had little effect and the anions had no effect on the acidity of [AAE]X. At the same time, the OIM, PTM, Hammett method and DFT method were reliable for determining the acidic strength of [AAE]X in this study.

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Brønsted acidity of protic ionic liquids: a modern ab initio valence bond theory perspective

Physical Chemistry Chemical Physics ◽

10.1039/c6cp04220a ◽

2016 ◽

Vol 18 (37) ◽

pp. 26020-26025 ◽

Cited By ~ 5

Author(s):

Amol Baliram Patil ◽

Bhalchandra Mahadeo Bhanage

Keyword(s):

Ionic Liquids ◽

Ab Initio ◽

A Priori ◽

Valence Bond ◽

Brønsted Acidity ◽

Protic Ionic Liquids ◽

Valence Bond Theory ◽

Brönsted Acidity ◽

Bond Theory

Modern ab initio valence bond theory calculations of representative primary and tertiary ammonium protic ionic liquids indicate that modern ab initio valence bond theory can be employed to assess the acidity and ionicity of protic ionic liquids a priori.

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