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Published on: December 20, 2016
A new proton conductive liquid with no ions: pseudo-protic ionic liquids
Hiroyuki Doi1, Xuedan Song, Babak Minofar
1Graduate School of Science and Technology, Niigata University, 8050, Ikarashi, 2no-cho, Nishi-ku, Niigata, 950-2181, Japan.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|July 23, 2013
Summary
This study reveals that N-methylimidazole and acetic acid mixtures primarily contain neutral molecules, despite exhibiting high ionic conductivity. Researchers propose calling these "pseudo-ionic liquids" due to their unique behavior.
Area of Science:
- Physical Chemistry
- Materials Science
- Electrochemistry
Background:
- Ionic liquids (ILs) are salts that are liquid below 100°C, widely used as electrolytes.
- Understanding the molecular structure and conductivity relationship in ILs is crucial for their application.
- N-methylimidazole and acetic acid mixtures present an interesting case for studying ionic behavior.
Purpose of the Study:
- To investigate the molecular composition and ionic conductivity of an equimolar N-methylimidazole and acetic acid mixture.
- To determine the extent of ionic versus neutral species in this mixture.
- To evaluate the suitability of the term 'pseudo-ionic liquid' for such systems.
Main Methods:
- Raman spectroscopy was employed to analyze the molecular species present.
- Quantum chemical calculations were performed to support the spectroscopic findings.
- Ionic conductivity measurements were conducted to assess the mixture's electrochemical properties.
Main Results:
- Raman analysis and quantum calculations indicate a predominance of electrically neutral molecular species.
- Ionic species were found to be present but in minor concentrations.
- The mixture exhibits significant ionic conductivity, characteristic of
- good ionic
- or
- superionic
- behavior.
Conclusions:
- The N-methylimidazole and acetic acid mixture behaves ionically despite being predominantly molecular.
- The term
- pseudo-ionic liquid
- is proposed as a more accurate descriptor for these systems.
- This finding challenges conventional definitions of ionic liquids and opens new avenues for electrolyte research.
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