Solvate and protic ionic liquids from aza-crown ethers: synthesis, thermal properties, and LCST behavior

Oba, Yukiko; Okuhata, Megumi; Osakai, Toshiyuki; Mochida, Tomoyuki

doi:10.1039/c7cp02807e

Cited by 4 publications

(2 citation statements)

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“…When mixed with trifluoromethanesulfonic acid (HTfO), an LCST phase transition was observed. In 2018, Mochida [69] synthesized solvate ILs and protic ILs by taking alkyl aza-crown ethers as ligands to coordinate with metal ions and other anions. Among them, solvate ILs coordinated with Na showed the LCST properties at a specific concentration, and T c has a downward trend with the increase in concentration.…”

Section: Zwitterionic Ionic Liquid Materials As Tilsmentioning

confidence: 99%

Expeditious Discovery of Small-Molecule Thermoresponsive Ionic Liquid Materials: A Review

Li,

Chu

2023

Molecules

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Ionic liquids (ILs) are a class of low-melting molten salts (<100 °C) constituted entirely of ions, and their research has gained tremendous attention in line with their remarkably growing applications (>124,000 publications dated 30 August 2023 from the Web of ScienceTM). In this review, we first briefly discussed the recent developments and unique characteristics of ILs and zwitterionic liquids (ZILs). Compared to molecular solvents and other conventional organic compounds, (zwitter) ionic liquids carry negligible volatility and are potentially recyclable and reusable. For structures, both ILs and ZILs can be systematically tailor-designed and engineered and are synthetically fine-tunable. As such, ionic liquids, including chiral, supported, task-specific ILs, have been widely used as powerful ionic solvents as well as valuable additives and catalysts for many chemical reactions. Moreover, ILs have demonstrated their value for use as polymerase chain reaction (PCR) enhancers for DNA amplification, chemoselective artificial olfaction for targeted VOC analysis, and recognition-based affinity extraction. As the major focus of this review, we extensively discussed that small-molecule thermoresponsive ILs (TILs) and ZILs (zwitterionic TILs) are new types of smart materials and can be expeditiously discovered through the structure and phase separation (SPS) relationship study by the combinatorial approach. Using this SPS platform developed in our laboratory, we first depicted the rapid discovery of N,N-dialkylcycloammonium and 1,3,4-trialkyl-1,2,3-triazolium TILs that concomitantly exhibited LCST (lower critical solution temperature) phase transition in water and displayed biochemically attractive Tc values. Both smart IL materials were suited for applications to proteins and other biomolecules. Zwitterionic TILs are ZILs whose cations and anions are tethered together covalently and are thermoresponsive to temperature changes. These zwitterionic TIL materials can serve as excellent extraction solvents, through temperature change, for biomolecules such as proteins since they differ from the common TIL problems often associated with unwanted ion exchanges during extractions. These unique structural characteristics of zwitterionic TIL materials greatly reduce and may avoid the denaturation of proteins under physiological conditions. Lastly, we argued that both rational structural design and combinatorial library synthesis of small-molecule TIL materials should take into consideration the important issues of their cytotoxicity and biosafety to the ecosystem, potentially causing harm to the environment and directly endangering human health. Finally, we would concur that before precise prediction and quantitative simulation of TIL structures can be realized, combinatorial chemistry may be the most convenient and effective technology platform to discover TIL expeditiously. Through our rational TIL design and combinatorial library synthesis and screening, we have demonstrated its power to discover novel chemical structures of both TILs and zwitterionic TILs. Undoubtedly, we will continue developing new small-molecule TIL structures and studying their applications related to other thermoresponsive materials.

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Section: Zwitterionic Ionic Liquid Materials As Tilsmentioning

confidence: 99%

Expeditious Discovery of Small-Molecule Thermoresponsive Ionic Liquid Materials: A Review

Li,

Chu

2023

Molecules

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“…For example, the complex stability with benzo-15-crown-5, 12crown-4, and 14-crown-4 CEs adsorbers have shown excellent complexation properties with Li + ; however, complexations with Mg 2+ and Na + were also possible. 18,[24][25][26][27][28][29][30][31][32] To selectively extract Li + from aqueous resources, the complexation behavior of Li + and the other metal ions is of great importance. Especially the complexation properties of Li + and Mg 2+ are of great interest since they have almost the same ion diameter in aqueous solution.…”

Section: Introductionmentioning

confidence: 99%