Tethered from the Head and from the Tail: The Structure of Hydroxyl-Functionalized Ionic Liquids

Ionic liquids with special functionalities are synthesized
with
the specific purpose of creating new patterns of interaction in the
condensed phase. This Letter discusses the case of alcohol-functionalized
ILs, the so-called HFILs, which are part of the larger cohort of task-specific
ionic liquids. We find that this small chemical modification can cause
massive changes in the liquid landscape when the cationic tails are
longer. For prototypical ionic liquids, larger alkyl tails act as
separators of charge networks, but in the case of HFILs these become
physical charge network linkers. The OH functionality adds a large
repertoire of interactions and correlations that were mostly unavailable
to traditional ILs.