Dynamics of Liquid 1-Ethyl-3-Methylimidazolium Acetate Measured with Implanted-Ion 8Li β-NMR

Derek Fujimoto; Ryan M.L. McFadden; Martin H. Dehn; Yael Petel; Aris Chatzichristos; Lars Bo Stegeager Hemmingsen; Victoria L. Karner; Robert F. Kiefl; C.D. Philip Levy; Iain McKenzie; Carl A. Michal; Gerald D. Morris; Matthew R. Pearson; Daniel Mihaly Szunyogh; John O. Ticknor; Monika Stachura; W. Andrew McFarlane

doi:10.1021/acs.chemmater.9b02864

Dynamics of Liquid 1-Ethyl-3-Methylimidazolium Acetate Measured with Implanted-Ion ⁸Li β-NMR

Derek Fujimoto, Ryan M.L. McFadden, Martin H. Dehn, Yael Petel, Aris Chatzichristos, Lars Bo Stegeager Hemmingsen, Victoria L. Karner, Robert F. Kiefl, C.D. Philip Levy, Iain McKenzie, Carl A. Michal, Gerald D. Morris, Matthew R. Pearson, Daniel Mihaly Szunyogh, John O. Ticknor, Monika Stachura, W. Andrew McFarlane

Department of Chemistry

1 Citation (Scopus)

Abstract

We demonstrate the application of implanted-ion β-detected NMR as a probe of ionic liquid molecular dynamics through the measurement of ⁸Li spin-lattice relaxation (SLR) and resonance in 1-ethyl-3-methylimidazolium acetate. The motional narrowing of the resonance and the local maxima in the SLR rate, 1/T₁, imply sensitivity to subnanosecond Li⁺ solvation dynamics. From an analysis of 1/T₁, we extract an activation energy EA = 74.8(1.5) meV and Vogel–Fulcher–Tammann constant TVFT = 165.8(0.9) K, in agreement with the dynamic viscosity of the bulk solvent. Near the melting point, the lineshape is broad and intense, and the form of the relaxation is nonexponential, reflective of our sensitivity to heterogeneous dynamics near the glass transition. The depth resolution of this technique may later provide a unique means of studying nanoscale phenomena in ionic liquids.

Original language	English
Journal	Chemistry of Materials
Volume	31
Issue number	22
Pages (from-to)	9346-9353
Number of pages	7
ISSN	0897-4756
DOIs	https://doi.org/10.1021/acs.chemmater.9b02864
Publication status	Published - 26 Nov 2019

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10.1021/acs.chemmater.9b02864

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Fujimoto, D., McFadden, R. M. L., Dehn, M. H., Petel, Y., Chatzichristos, A., Hemmingsen, L. B. S., Karner, V. L., Kiefl, R. F., Levy, C. D. P., McKenzie, I., Michal, C. A., Morris, G. D., Pearson, M. R., Szunyogh, D. M., Ticknor, J. O., Stachura, M., & McFarlane, W. A. (2019). Dynamics of Liquid 1-Ethyl-3-Methylimidazolium Acetate Measured with Implanted-Ion ⁸Li β-NMR. Chemistry of Materials, 31(22), 9346-9353. https://doi.org/10.1021/acs.chemmater.9b02864

Fujimoto, D, McFadden, RML, Dehn, MH, Petel, Y, Chatzichristos, A, Hemmingsen, LBS, Karner, VL, Kiefl, RF, Levy, CDP, McKenzie, I, Michal, CA, Morris, GD, Pearson, MR, Szunyogh, DM, Ticknor, JO, Stachura, M & McFarlane, WA 2019, 'Dynamics of Liquid 1-Ethyl-3-Methylimidazolium Acetate Measured with Implanted-Ion ⁸Li β-NMR', Chemistry of Materials, vol. 31, no. 22, pp. 9346-9353. https://doi.org/10.1021/acs.chemmater.9b02864

@article{747d66ee29ca4c9da20575c178ce868c,

title = "Dynamics of Liquid 1-Ethyl-3-Methylimidazolium Acetate Measured with Implanted-Ion 8Li β-NMR",

abstract = "We demonstrate the application of implanted-ion β-detected NMR as a probe of ionic liquid molecular dynamics through the measurement of 8Li spin-lattice relaxation (SLR) and resonance in 1-ethyl-3-methylimidazolium acetate. The motional narrowing of the resonance and the local maxima in the SLR rate, 1/T1, imply sensitivity to subnanosecond Li+ solvation dynamics. From an analysis of 1/T1, we extract an activation energy EA = 74.8(1.5) meV and Vogel–Fulcher–Tammann constant TVFT = 165.8(0.9) K, in agreement with the dynamic viscosity of the bulk solvent. Near the melting point, the lineshape is broad and intense, and the form of the relaxation is nonexponential, reflective of our sensitivity to heterogeneous dynamics near the glass transition. The depth resolution of this technique may later provide a unique means of studying nanoscale phenomena in ionic liquids.",

author = "Derek Fujimoto and McFadden, {Ryan M.L.} and Dehn, {Martin H.} and Yael Petel and Aris Chatzichristos and Hemmingsen, {Lars Bo Stegeager} and Karner, {Victoria L.} and Kiefl, {Robert F.} and Levy, {C.D. Philip} and Iain McKenzie and Michal, {Carl A.} and Morris, {Gerald D.} and Pearson, {Matthew R.} and Szunyogh, {Daniel Mihaly} and Ticknor, {John O.} and Monika Stachura and McFarlane, {W. Andrew}",

year = "2019",

month = nov,

day = "26",

doi = "10.1021/acs.chemmater.9b02864",

language = "English",

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journal = "Chemistry of Materials",

issn = "0897-4756",

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TY - JOUR

T1 - Dynamics of Liquid 1-Ethyl-3-Methylimidazolium Acetate Measured with Implanted-Ion 8Li β-NMR

AU - Fujimoto, Derek

AU - McFadden, Ryan M.L.

AU - Dehn, Martin H.

AU - Petel, Yael

AU - Chatzichristos, Aris

AU - Hemmingsen, Lars Bo Stegeager

AU - Karner, Victoria L.

AU - Kiefl, Robert F.

AU - Levy, C.D. Philip

AU - McKenzie, Iain

AU - Michal, Carl A.

AU - Morris, Gerald D.

AU - Pearson, Matthew R.

AU - Szunyogh, Daniel Mihaly

AU - Ticknor, John O.

AU - Stachura, Monika

AU - McFarlane, W. Andrew

PY - 2019/11/26

Y1 - 2019/11/26

N2 - We demonstrate the application of implanted-ion β-detected NMR as a probe of ionic liquid molecular dynamics through the measurement of 8Li spin-lattice relaxation (SLR) and resonance in 1-ethyl-3-methylimidazolium acetate. The motional narrowing of the resonance and the local maxima in the SLR rate, 1/T1, imply sensitivity to subnanosecond Li+ solvation dynamics. From an analysis of 1/T1, we extract an activation energy EA = 74.8(1.5) meV and Vogel–Fulcher–Tammann constant TVFT = 165.8(0.9) K, in agreement with the dynamic viscosity of the bulk solvent. Near the melting point, the lineshape is broad and intense, and the form of the relaxation is nonexponential, reflective of our sensitivity to heterogeneous dynamics near the glass transition. The depth resolution of this technique may later provide a unique means of studying nanoscale phenomena in ionic liquids.

AB - We demonstrate the application of implanted-ion β-detected NMR as a probe of ionic liquid molecular dynamics through the measurement of 8Li spin-lattice relaxation (SLR) and resonance in 1-ethyl-3-methylimidazolium acetate. The motional narrowing of the resonance and the local maxima in the SLR rate, 1/T1, imply sensitivity to subnanosecond Li+ solvation dynamics. From an analysis of 1/T1, we extract an activation energy EA = 74.8(1.5) meV and Vogel–Fulcher–Tammann constant TVFT = 165.8(0.9) K, in agreement with the dynamic viscosity of the bulk solvent. Near the melting point, the lineshape is broad and intense, and the form of the relaxation is nonexponential, reflective of our sensitivity to heterogeneous dynamics near the glass transition. The depth resolution of this technique may later provide a unique means of studying nanoscale phenomena in ionic liquids.

U2 - 10.1021/acs.chemmater.9b02864

DO - 10.1021/acs.chemmater.9b02864

M3 - Journal article

SN - 0897-4756

VL - 31

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JO - Chemistry of Materials

JF - Chemistry of Materials

IS - 22

ER -