Intermolecular interactions in mixtures of 1-n-butyl-3-methylimidazolium acetate and water: Insights from IR, Raman, NMR spectroscopy and quantum chemistry calculations

Local Structure in Terms of Nearest-Neighbor Approach in 1-Butyl-3-methylimidazolium-Based Ionic Liquids: MD Simulations

“…This claim has been experimentally confirmed in neat ILs via the isotopic shift of 19 F NMR signals after selective deuteration of the C 4 mim + cation in C 4 mimBF 4 and C 4 mimPF 6 , 75 and also in their solutions in various molecular solvents, from concentration dependent chemical shifts. 17,[22][23] Similarly to Figure 4, we present in Figure 7 the CDFs relating the H-bonding distance and the corresponding pseudovalent angle between different alkyl hydrogen atoms of the C 4 mim + cation and the nearest neighboring H-bond accepting atom of the anions. Not surprisingly, the H-bonds involving the alkyl hydrogen atoms are less frequent (note the scale used in Figure 7 is half of that in Figure 4), longer, and deviate more from the linear arrangement than those involving the imidazolium ring C-H sites.…”

“…3,[27][28][29][30] Regarding the use of molecular simulations in explaining various spectroscopic observations one has to keep in mind that the vast majority of such experimental information reports the local molecular environment around specific sites of IL cations, e.g., 1 H NMR signals, CH vibrational bands, etc. [22][23][31][32][33][34] The importance of studying the influence of the anions on the microscopic structure around a reference cation is evident in this context.…”

Two‐dimensional Raman spectroscopy study of ionogel phase formation in long‐chain ionic liquid/water systems

“…The simultaneous appearance of a smectic LC phase indicates that the formation of H bonds between imidazolium rings, mediated by a channel of water, provides enhanced ordering of the parallel molecular layers . Previous NMR, quantum chemistry calculations, and vibrational spectroscopy studies claim that the most pronounced dependence of chemical shift on amount of water was observed for H‐bonded C(2)‐H … Br bridge proton, while the weakest effect was detected for the terminal methyl group, C(16)‐H 3 . Further addition of water caused IL/water system conversion from liquid to the gel phase.…”

Multinuclear NMR and diffusion studies of quaternary amine‐based ionic liquids

“…17 O NMR is also a valuable probe for characterization of intermolecular interactions due to its large chemical range. There are several reports on the application of 17 O NMR in the solid state, but it is still rare to see 17 O NMR in the liquid state, especially for ILs . 17 O spectra of the ILs probed in this letter are shown in Fig.…”