Solvation and aggregation of n,n'-dialkylimidazolium ionic liquids: a multinuclear NMR spectroscopy and molecular dynamics simulation study.
The solvation and aggregation of the ionic liquid (IL) 1-n-butyl-3-methylimidazolium chloride ([C4mim]Cl) in water and dimethylsulfoxide (DMSO) were examined by analysis of (1)H and (35/37)Cl chemical shift perturbations and molecular dynamics (MD) simulations. Evidence of aggregation of the IL n-butyl chains in aqueous environments at IL concentrations of 75-80 wt% was observed both in the NMR experiments and in the MD simulations. The studies also show that [C4mim]Cl behaves as a typical electrolyte in water, with both ions completely solvated at low concentrations. On the other hand, the data reveal that the interactions between the [C4mim](+) and Cl(-) ions strengthen as the DMSO content of the solutions increases, and IL-rich clusters persist in this solvent even at concentrations below 10 wt%. These results provide an experimentally supported atomistic explanation of the effects that these two solvents have on some of the macroscopic properties of [C4mim]Cl. The implications that these findings could have on the design of IL-based solvent systems are briefly discussed.
Remsing
Richard C
RC
Department of Chemistry & Biochemistry and West Center for Computational Chemistry and Drug Design, University of the Sciences in Philadelphia, 600 South 43rd Street, Philadelphia, Pennsylvania 19104-4495, USA. g.moyna@usp.edu
Liu
Zhiwei
Z
Sergeyev
Ivan
I
Moyna
Guillermo
G
D000478:Alkylation; D003198:Computer Simulation; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D012995:Solubility
D007093:Imidazoles; D052578:Ionic Liquids; D007477:Ions