Spectral characteristics of ethylene sorbed by silver-containing ionic liquids studied by in situ ATR-FTIR spectroscopy

The spectral characteristics of ethylene absorbed by ionic liquids (ILs) containing silver ions were studied by in situ ATR-FTIR spectroscopy at high pressure. Three different states of ethylene were observed based on the band shift of out-of-plane bending vibrations (ωCH₂) due to van der Waals interactions, hydrogen bonds, and π-complex formation with silver ions. Thus, ethylene can be used as an IR-sensitive probe molecule for characterizing interactions with ILs and other substances.