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From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Broadband Terahertz Spectroscopy of Imidazolium-Based Ionic Liquids
Sen Mou1, Andrea Rubano1,2, Domenico Paparo2
1Dipartimento di Fisica "Ettore Pancini" , Università di Napoli "Federico II", Complesso Universitario di Monte Sant'Angelo , via Cintia , 80126 Napoli , Italy.
Abstract:
Ionic liquids are liquid salts at ambient temperature composed of organic cations and organic/inorganic anions. Outstanding physical and chemical properties of ionic liquids lead to increasing application in scientific and industrial field. Ionic liquids have been already investigated by different spectroscopic techniques, including terahertz (THz) time-domain spectroscopy. The usual THz frequency range extends up to 2-3 THz, a relatively narrow band, which can only show the intermolecular vibrational modes. Here, we report about broadband THz spectroscopy of ionic liquids up to 13 THz. Bandwidth of intermolecular absorption band presents an unexpected behavior and strong sharp intramolecular absorptions are shown. In addition, we found violation of the approximation of harmonic oscillator used to predict the peak shift of intermolecular absorption band.
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