Ionic liquids: "normal" solvents or nanostructured fluids?

Area of Science:

• Green Chemistry
• Physical Chemistry
• Organic Chemistry

Background:

• Ionic liquids (ILs) are versatile, non-conventional solvents with growing importance in chemical research.
• Understanding the impact of ILs on organic reactivity is crucial for optimizing chemical processes.

Purpose of the Study:

• To review literature from 2010 to present on the influence of ILs on organic reactivity and reaction rates.
• To present two primary theoretical frameworks explaining IL solvent effects: bulk polarity and nanostructure.
• To cover studies on IL mixtures and supramolecular catalysis in ILs.

Main Methods:

• Literature review of scientific publications from 2010 onwards.
• Analysis of studies explaining IL solvent effects through bulk polarity and linear solvation energy relationships.
• Examination of research treating ILs as nanostructured fluids.
• Inclusion of studies on IL mixtures and supramolecular catalysis.

Main Results:

• ILs significantly alter organic reactivity and reaction rates through their unique solvent properties.
• Two main mechanistic viewpoints explain IL effects: bulk polarity/LSER and nanostructure.
• IL mixtures and supramolecular catalysis in ILs are also key areas of investigation.

Conclusions:

• ILs offer tunable environments that profoundly affect organic transformations.
• The interplay between IL bulk properties and nanostructure dictates their influence on reactivity.
• This review provides a framework for future research on ILs in organic synthesis and catalysis.