Brønsted acidity of bio-protic ionic liquids: the acidic scale of [AA]X amino acid ionic liquids

2015 ◽  
Vol 17 (12) ◽  
pp. 5154-5163 ◽  
Author(s):  
Lei Zhang ◽  
Ling He ◽  
Cheng-Bin Hong ◽  
Song Qin ◽  
Guo-Hong Tao
Keyword(s):  
Ionic Liquids ◽  
Amino Acid ◽  
Brønsted Acidity ◽  
Protic Ionic Liquids ◽  
Brönsted Acidity

The Brønsted acidity of typical “bio-base” protic ionic liquids, [AA]X amino acid ionic liquids, was systematically studied.

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

Molecules ◽  
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.

Effect of Brønsted Acidity on Ion Conduction in Fluorinated Acetic Acid and N-Methylimidazole Equimolar Mixtures as Pseudo-protic Ionic Liquids

2020 ◽  
Vol 124 (49) ◽  
pp. 11157-11164
Author(s):  
Hikari Watanabe ◽  
Nana Arai ◽  
Yasuo Kameda ◽  
Richard Buchner ◽  
Yasuhiro Umebayashi
Keyword(s):  
Acetic Acid ◽  
Ionic Liquids ◽  
Brønsted Acidity ◽  
Protic Ionic Liquids ◽  
Ion Conduction ◽  
Brönsted Acidity

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

2018 ◽  
Vol 269 ◽  
pp. 178-186 ◽  
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

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

2016 ◽  
Vol 18 (37) ◽  
pp. 26020-26025 ◽  
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.

Brønsted acidity in deep eutectic solvents and ionic liquids

2018 ◽  
Vol 206 ◽  
pp. 365-377 ◽  
Author(s):  
Andrew P. Abbott ◽  
Sahar S. M. Alabdullah ◽  
Azhar Y. M. Al-Murshedi ◽  
Karl S. Ryder
Keyword(s):  
Ionic Liquids ◽  
Deep Eutectic Solvents ◽  
Glass Electrode ◽  
Brønsted Acidity ◽  
Ph Values ◽  
Brönsted Acidity ◽  
Indicator Dye

Relative pH values are calculated using an indicator dye and a glass electrode, and they are found to provide consistent results.

Metal-free hydroxyl functionalized quaternary phosphine type ionic liquids polymer for cycloaddition of CO2 and epoxide

2021 ◽  
Author(s):  
Wuying Zhang ◽  
Qian He ◽  
Yaju Chen ◽  
Rongchang Luo ◽  
Xiantai Zhou ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Synergistic Effect ◽  
Hydroxyl Group ◽  
Brønsted Acidity ◽  
Metal Free ◽  
Brönsted Acidity ◽  
Free Hydroxyl ◽  
Alkylation Reactions

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...

Amino Acid-derived Protic Ionic Liquids: Physicochemical Properties and Behaviour as Amphiphile Self-assembly Media

2011 ◽  
Vol 64 (2) ◽  
pp. 180 ◽  
Author(s):  
Jiayi Wang ◽  
Tamar L. Greaves ◽  
Danielle F. Kennedy ◽  
Asoka Weerawardena ◽  
Gonghua Song ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Amino Acid ◽  
Methyl Ester ◽  
Physicochemical Properties ◽  
Self Assembly ◽  
Ionic Surfactant ◽  
Hexadecyltrimethylammonium Bromide ◽  
Structure Property ◽  
Protic Ionic Liquids ◽  
Fused Salts

The thermal phase transitions and physicochemical properties of a series of 21 amino acid-derived protic ionic liquids and four protic molten salts have been investigated. Structure–property comparisons for this series were investigated for alkyl- and cyclic amino acid cations, and ethoxy and methoxy groups on the cation, combined with nitrate or various carboxylate-containing anions. All the protic fused salts were found to be ‘fragile’. Most of the protic fused salts exhibited a glass transition, with the transition temperatures ranging from –90° to –42°C. Viscosities and conductivities ranged from 0.03 to 15.46 Pa s and 0.02 to 2.20 mS cm–1 at 25°C respectively. The protic ionic liquids alanine methyl ester glycolate, proline methyl ester nitrate, and proline methyl ester glycolate were found to be capable of supporting amphiphile self-assembly. Lamellar or hexagonal liquid crystalline phases were observed with the cationic surfactant hexadecyltrimethylammonium bromide and the non-ionic surfactant Myverol 18–99K.

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

2015 ◽  
Vol 51 (30) ◽  
pp. 6651-6654 ◽  
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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