Liquid that consists exclusively or almost exclusively of equivalent amounts of oppositely charged ions.
Notes: - In practice, the ions are monocations and monoanions.
- Ionic liquids that are liquid at or around room temperature are called room-temperature ionic liquids (RTILs).
- The term ionic liquid has been often restricted to those water-free liquids that have melting points (or glass-transition temperatures) below \(\pu{100 ^{\circ}C}\), following a definition given by Walden, who prepared the first ionic liquid, ethylammonium nitrate, \(\ce{CH3CH2NH3^{+}NO3^{-}}\), mp. \(\pu{13\!-\! 14 ^{\circ}C}\), for conductivity measurements.
- The terminology for ionic liquids is not yet settled, as stated by Welton. Room-temperature ionic liquid, non-aqueous ionic liquid, molten salt, liquid organic salt, and fused salt are often synonymous.
Source:
PAC, 2022, 94, 353. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021)' on page 442 (https://doi.org/10.1515/pac-2018-1010)