An insight into the intermolecular vibrational modes of dicationic ionic liquids through far-infrared spectroscopy and DFT calculations

Abstract

The minimal cluster of ions represents a reliable and computationally affordable model for the exploration of the intermolecular interactions of dicationic ionic liquids.

Pseudo-Optical Modes in Room-Temperature Ionic Liquids

“…That could be done using the so-called instantaneous normal-mode analysis, ,, being a possible starting point for future investigations. The ionic pair ansatz has been widely used for quantum chemical calculations and has been an interesting approach to obtain the displacement coordinates of this mode observed in FIR spectra of RTILs. − ,, Herein, by relying on a model from a quasi-lattice perspective, we have given a complementary interpretation of the same phenomenology.…”

Insights into cation–anion hydrogen bonding in mesogenic ionic liquids: an NMR study

“…For example, the predicted U-shape conformation of cations makes charged group well accessible for anion Hbonding. 40,41 On the other hand, in the smectic phase discussed below, the layered assembly of cations may impose constraints on cation conformational dynamics and alignment of the imidazolium group and the side chains. 10,36,37 In protic ILCs based on the cation C 12 im, the primary centre for HB is shifted to NH protons and thus HB to CH protons weakens.…”

Effect of Bulky Anion around the Dication on the Electronic Structure and Normal Frequencies in 1,3-Bis(3-methylimidazolium-1-yl)propane Bis(trifluoromethanesulfonyl)imide Ionic Liquid

“…In addition to physical properties, the intermolecular interactions, and consequently, the position of these anions around the dication play an important role in the expansion of the network structures, such as larger clusters of ion pairs in the liquid phase. 7 …”

“…In analogy with the characterization of the ILs, the factors affecting the physicochemical properties of DILs are mainly the relatively higher number of interactions between the anions and cations and the length of alkyl chains. In addition to physical properties, the intermolecular interactions, and consequently, the position of these anions around the dication play an important role in the expansion of the network structures, such as larger clusters of ion pairs in the liquid phase …”

“…In addition to physical properties, the intermolecular interactions, and consequently, the position of these anions around the dication play an important role in the expansion of the network structures, such as larger clusters of ion pairs in the liquid phase. 7 Vibrational spectroscopy is an invaluable option for a deeper understanding of the interactions and structures of ILs. 8 IR and Raman spectroscopy are popular and provide information about the nature of the interactions and their consequences in the vibrational spectra.…”