Abstract
The intermolecular interactions in a hybrid electrolyte based on various compositions of the ionic liquid N-methyl-N-propyl pyrrolidinium bis-fluorosulfonylimide (C3mpyrFSI), LiFSI salt and an ether-based additive, 1,2-dimethoxy ethane (DME), have been investigated using the HOESY (Heteronuclear Overhauser Effect SpectroscopY) NMR experiment. This NMR technique allows a quantification of the intermolecular interactions in ionic liquids (ILs) by measuring the cross-relaxation rate (σ) between different pairs of nuclei. Thereby, we compare the cross-relaxation rates between the cations, anions and DME in these hybrid electrolyte systems using 1H-7Li and 1H-19F HOESY experiments, and interpret the measured parameters in terms of ionic and molecular associations. The results give insights into the local coordination environment of the Li+ cations and their solvation by the FSI anions and DME.
Highlights
Ionic liquids (ILs), typically consisting of an organic cation and an inorganic anion, have gained a lot of attention from researchers over the last two decades (Weingärtner, 2013)
In our recent work on Heteronuclear Overhauser Effect SpectroscopY (HOESY) (Martin et al, 2018b), we demonstrated the importance of taking into account both the longitudinal relaxation times and self-diffusion coefficients of the nuclear spins when fitting HOESY build-up curves, as well as the normalization of the measured signals to the equilibrium magnetization
The peak at around 3.8 ppm in the HOESY spectra was fitted to a single cross-relaxation rate assumed to reflect only that of the site 7 protons on the dimethoxy ethane (DME) molecule
Summary
Ionic liquids (ILs), typically consisting of an organic cation and an inorganic anion, have gained a lot of attention from researchers over the last two decades (Weingärtner, 2013). We quantitatively measure the Overhauser cross-relaxation rates in this DME-based hybrid ionic liquid electrolyte system for the intermolecular heteronuclear spin pairs 1H-19F and 1H-7Li. The results provide insights into the ionic associations and lithium cation solvation environment via the interactions between the
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
