Probing the local structure of ionic liquid salts with 35 Cl , 79 Br and 127 I solid - and liquid - state NMR

Ionic liquids (IL) have been known for nearly a century but are recently garnering increased interest due to their unique characteristics. The term “room temperature ionic liquid” (RTIL) is often used interchangeably with “ionic liquid” and is by convention defined as an organic salt with a melting point ca. 100 °C or less. RTILs are considered part of the green chemistry paradigm due to their negligible vapour pressure and ease of recycling. A broad spectrum of tunable properties arises from the customizability of the organic cation and the variety of cation-anion pairings. A great deal of recent effort has gone into the characterization of ionic liquids in order to determine if they have properties that are uniquely different from other liquids. Evidence of liquid state order, observed by IR and Raman spectroscopy, diffraction studies, and simulated by ab initio methods, has been reported in the literature.