Two-Dimensional IR Spectroscopy as a Window into the Molecular Structure and Dynamics of Electrolytes and Ionic Liquids: A Review

In electrolytes and ionic liquids, where physicochemical properties arise from the interplay between solvation and ionic interactions, 2DIR spectroscopy provides unique insights into intermolecular interactions and dynamical processes that are often inaccessible to conventional spectroscopies.

This review highlights seminal and recent advances in understanding the behavior of these systems using 2DIR spectroscopy, with particular emphasis on spectral diffusion, vibrational relaxation, and chemical exchange dynamics. The review also describes how complementary information from the vibrational modes of solvents, salts, and external probes enables detailed characterization of ion–ion interactions, hydrogen-bonding networks, and solvation environments, providing a molecular framework of the structure and time evolution of these charged systems.