Density functional theory study on the –SO3H functionalized acidic ionic liquids

Abstract

In this work, the structures of the -SO 3 H functionalized acidic ionic liquid 1-(3-sulfonic acid) propyl-3-methylimidazolium hydrogen sulfate ([C 3 SO 3 Hmim]HSO 4 ), including its precursor compound (zwitterion), cation, and cation-anion ion-pairs, were optimized systematically by the DFT theory at B3LYP/6-311??G** level, and their most stable geometries were obtained. The calculation results indicated that a great tendency to form strong intramolecular hydrogen bonds was present in the zwitterion, and this tendency was weakened in the cation that was the protonation product of zwitterion. The intramolecular hydrogen bonds and intermolecular hydrogen bonds coexisted in the ionic liquid, and they played an important role in the stability of the systems. The strongest interaction in the ionic liquid was found between the anion and the functional group. The transition state research and the intrinsic reaction coordinate analysis of the hydrogen transfer reaction showed that, when the cation and the anion interacted near the functional group by double O-HÁÁÁO hydrogen bonds, the ionic liquid was inclined to exist in a form of the zwitterion and H 2 SO 4 .

“Release and Catch” Effect of Perfluoroalkylsulfonylimide‐Functionalized Imidazole/Pyridine on Brønsted Acids in Organic Systems

“…This fluid was analysed by using NMR spectroscopy,w hich revealed that it was composed mainly of 4a and TfOH (Figure 3). The shift of the water peak from d = 3.334 to 7.234 ppm in the 1 HNMR spectrum of 4a/TfOH was attributed to the combination with acidic protons, and the new signal at d = À77.874 ppm in the 19 FNMR spectrum was from the CF 3 SO 3 À counter-anion. Meanwhile, as mall amount of TfOH was detectedi nt he organic phase.At itration method was employed to quantify the proportion of TfOH in both the organic andi onic phases.B efore titration, the organic phase was extracted with water.T he ionic phasew as washedf irst with ethyl acetate, and the obtained ethyl acetate phase was extracted conversely by water.I nt he titration experiment,a n aqueous solution of NaOH (0.02 mol L À1 )w as used.…”

“…[ D 6 ]Acetone, [D 6 ]DMSO and CDCl 3 were purchased from Alfa Aesar.E thyl acetate, toluene, nitromethane, potassium carbonate, acetone, methanol and ethanol were all purchased from Sinopharm Chemical Reagents Limited Company. 1 H, 13 C, 19 Fa nd 31 PNMR spectra were recorded by using aB ruker AV-400 spectrometer.C hemical shifts are expressed in ppm relative to Me 4 Si in CDCl 3 or [D 6 ]DMSO, or to Ph 2 ClP=O. MS was recorded by using an Agilent LC-MSD-Trap-XCT instrument.…”

“…The counter‐anion of the SO 3 H‐style IL preferred to be close to the SO 3 H group rather than the imidazole ring. Thus, the SO 3 H‐style IL existed in the form of a zwitterion and strong acid with an easy H‐shift from the strong acid to the zwitterion to form the counter‐anion and the SO 3 H group . Dhaked and Bharatam performed a computational analysis that showed, under implicit polar solvent conditions, that the zwitterionic isomer in 4‐amino‐pyridyl‐3‐sulfonylurea was nearly isoenergetic with the canonical form, which was even predominant under the influence of water molecules .…”

Novel guanidinium zwitterion and derived ionic liquids: physicochemical properties and DFT theoretical studies

“…The DFT has a great capability in obtaining information about the energetics, structure, and electron properties of atoms or molecules. The previous investigations proved that the DFT method was suitable for calculation of ILs [39][40][41][42][43]. In 2006, Zhang and co-workers [44] exploited a new force field based on AMBER for molecular dynamics (MD) simulation of acyclic guanidinium-based ILs and found that the predicted densities were in good agreement with the experimental data.…”

Solid, Solution and Gas Phase Interactions of an Imidazolium-Based Task-Specific Ionic Liquid Derived from Natural Kojic Acid

“…2 Besides ionic interactions, whether supramolecular interactions also govern the organization of imidazoliumbased ILs is still hotly debated with a vast number of important contributions. [24][25][26][27][28][29] Despite their importance, the number of significant contributions specifically discussing the supramolecular organization and interactions of TSILs is much scarcer [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] when compared to nonfunctionalized ILs. TSILs have become one of the most important strategies for furthering IL chemistry, 1 as noted for the large and increasing number of innovative applications described for these ionic compounds.…”