[PDF]     https://doi.org/10.3952/physics.2026.66.2.1

Open access article / Atviros prieigos straipsnis
Lith. J. Phys. 66, 69–74 (2026)
 

NON-ARRHENIUS BEHAVIOUR OF NMR SELF-DIFFUSION OF THE NEAT ROOM TEMPERATURE IONIC LIQUID 1-BUTYL-3-METHYL IMIDAZOLIUM TETRAFLUOROBORATE [BMIM][BF4]
 Vytautas Klimavičiusa and Zofia Gdaniecb
aInstitute of Chemical Physics, Vilnius University, Saulėtekio 3, 10257 Vilnius, Lithuania
bInstitute of Bioorganic Chemistry, Polish Academy of Sciences, Z. Noskowskiego 12/14, 61704 Poznan, Poland
Email: vytautas.klimavicius@ff.vu.lt

Received 28 November 2025; accepted 21 January 2026

Room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) was investigated using 1H, 19F, 11B and 10B DOSY NMR spectroscopy in a temperature range of 288–338 K. The dynamics of the [BF4] anion and [bmim] cation have been found to be similar, indicating that both constituents behave as a rigid unit in the studied temperature range. The diffusion coefficients varied from 6.9 ∙ 10–11 m2 s–1 at the highest temperature to 6.1 ∙ 10–12 m2 s–1 at the lowest temperature. The dynamics of the diffusion coefficient was found not obeying the Arrhenius law and therefore was analyzed using the Vogel–Fulcher–Tammann (VFT) equation for the diffusivity. The glass transition temperature was found to be in a range of 172–181 K, which coincides with the values obtained using other techniques and found in the literature; the parameter B which is related to activation energy was found equal to 828–1115 K.
Keywords: NMR, ionic liquids, diffusion, DOSY


NE ARENIJAUS TIPO DIFUZIJA JONINIAME SKYSTYJE 1-BUTIL-3-METILIMIDAZOLIO TETRAFLUOROBORATE [BMIM][BF4], TIRTA DOSY BMR METODU
  Vytautas Klimavičiusa, Zofia Gdaniecb
aVilniaus universiteto Fizikos fakulteto Cheminės fizikos institutas, Vilnius, Lietuva
bLenkijos mokslų akademijos Bioorganinės chemijos institutas, Poznanė, Lenkija
 
Kambario temperatūros joninis skystis (RTIL) 1-butil-3-metilimidazolio tetrafluoroboratas ([bmim][BF4]) buvo tirtas 288–338 K temperatūrų intervale naudojant 1H, 19F, 11B ir 10B DOSY (Diffusion Ordered Spectroscopy) branduolių magnetinio rezonanso (BMR) spektroskopiją. Nustatyta, kad [BF4] anijono ir [bmim] katijono dinamika yra palyginama, todėl galima teigti, jog RTIL dinamika yra vienoda tirtame temperatūrų intervale. Difuzijos koeficientai kito nuo 6,9 ∙ 10–11 m2/s esant aukščiausiai temperatūrai iki 6,1 ∙ 10–12 m–2/s esant žemiausiai temperatūrai. Nustatyta, kad difuzijos koeficiento temperatūrinė priklausomybė neatitinka Arenijaus dėsnio, todėl ji buvo analizuota naudojant Vogelio–Fulcherio–Tammanno (VFT) lygtį difuzijos procesui aprašyti. Tirtajam RTIL stiklėjimo temperatūra nustatyta 172–181 K intervale; ši vertė sutampa su reikšmėmis, gautomis kitais metodais ir pateikiamomis literatūroje. Parametras B, susijęs su aktyvacijos energija, nustatytas lygus 828–1115 K.


References / Nuorodos

[1] R.D. Rogers and K.R. Seddon, Ionic liquids – solvents of the future?, Science 302(5646), 792–793 (2003),
https://doi.org/10.1126/science.1090313
[2] N.V. Plechkova and K.R. Seddon, Applications of ionic liquids in the chemical industry, Chem. Soc. Rev. 37(1), 123–150 (2008),
https://doi.org/10.1039/B006677J
[3] F. Javed, F. Ullah, M.R. Zakaria, and H.M. Akil, An approach to classification and hi-tech applications of room-temperature ionic liquids (RTILs): A review, J. Mol. Liq. 271, 403–420 (2018),
https://doi.org/10.1016/j.molliq.2018.09.005
[4] H. Kaur, A. Thakur, R.C. Thakur, and A. Kumar, A review on multifaceted role of ionic liquids in modern energy storage systems: From electrochemical performance to environmental sustainability, Energy Fuels 39(8), 3703–3734 (2025),
https://doi.org/10.1021/acs.energyfuels.4c05274
[5] K. Matuszek, S.L. Piper, A. Brzęczek-Szafran, B. Roy, S. Saher, J.M. Pringle, and D.R. MacFarlane, Unexpected energy applications of ionic liquids, Adv. Mater. 36(23), e2313023 (2024),
https://doi.org/10.1002/adma.202313023
[6] Ž. Murnikova, V. Klimavicius, F. Mocci, A. Laaksonen, and K. Aidas, On the mechanism behind the enhanced solubility of glibenclamide in aqueous ionic liquid solution, J. Mol. Liq. 422, 127153 (2025),
https://doi.org/10.1016/j.molliq.2025.127153
[7] B. Kanjilal, Y. Zhu, V. Krishnadoss, J.M. Unagolla, P. Saemian, A. Caci, D. Cheraghali, I. Dehzangi, A. Khademhosseini, and I. Noshadi, Bioionic liquids: Enabling a paradigm shift toward advanced and smart biomedical applications, Adv. Intell. Syst. 5(5), 2200306 (2023),
https://doi.org/10.1002/aisy.202200306
[8] E. Sipavičius, L. Mikalauskas, V. Klimavicius, and K. Aidas, Intermolecular organization in aqueous mixtures of choline lysinate studied via NMR and molecular dynamics/quantum mechanics, Phys. Chem. Chem. Phys. 27(28), 14790–14803 (2025),
https://doi.org/10.1039/D5CP00861A
[9] R.F. Frade and C.A. Afonso, Impact of ionic liquids in environment and humans: An overview, Hum. Exp. Toxicol. 29(12), 1038–1054 (2010),
https://doi.org/10.1177/0960327110371259
[10] H. Tokuda, K. Ishii, M.A.B.H. Susan, S. Tsuzuki, K. Hayamizu, and M. Watanabe, Physicochemical properties and structures of room-temperature ionic liquids. 3. Variation of cationic structures, J. Phys. Chem. B 110(6), 2833–2839 (2006),
https://doi.org/10.1021/jp053396f
[11] X. Han and D.W. Armstrong, Ionic liquids in separations, Acc. Chem. Res. 40(11), 1079–1086 (2007),
https://doi.org/10.1021/ar700044y
[12] M. Salanne, Ionic liquids for supercapacitor applications, Top. Curr. Chem. 375, 63 (2017),
https://doi.org/10.1007/s41061-017-0150-7
[13] J. Wang, L. Xu, G. Jia, and J. Du, Challenges and opportunities of ionic liquid electrolytes for rechargeable batteries, Cryst. Growth Des. 22(9), 5770–5784 (2022),
https://doi.org/10.1021/acs.cgd.2c00706
[14] S. Rana, R.C. Thakur, and H.S. Dosanjh, Ionic liquids as battery electrolytes for lithium-ion batteries: Recent advances and future prospects, Solid State Ion. 400, 116340 (2023),
https://doi.org/10.1016/j.ssi.2023.116340
[15] P. Wasserscheid and W. Keim, Ionic liquids – new 'solutions' for transition metal catalysis, Angew. Chem. Int. Ed. 39(21), 3772–3789 (2000),
https://doi.org/10.1002/1521-3773(20001103)39:21<3772::AID-ANIE3772>3.0.CO;2-5
[16] J.P. Stoppelman and J.G. McDaniel, Proton transport in [BMIM+][BF4⁻]/water mixtures near the percolation threshold, J. Phys. Chem. B 124(28), 5957–5970 (2020),
https://doi.org/10.1021/acs.jpcb.0c02487
[17] Y.H. Yu, A.N. Soriano, and M.H. Li, Heat capacity and electrical conductivity of aqueous mixtures of [Bmim][BF4] and [Bmim][PF6], J. Taiwan Inst. Chem. Eng. 40(2), 205–212 (2009),
https://doi.org/10.1016/j.jtice.2008.09.006
[18] E. Sipavičius, G. Majauskaitė, D. Lengvinaitė, S. Bielskutė, V. Klimavicius, F. Mocci, A. Laaksonen, and K. Aidas, Towards accurate modelling of 1H NMR spectra of ionic liquids: The case of [C4mim][BF4] and its aqueous mixtures, Chem. Phys. Lett. 876, 142295 (2025),
https://doi.org/10.1016/j.cplett.2025.142295
[19] K. Damodaran, Recent advances in NMR spectroscopy of ionic liquids, Prog. Nucl. Magn. Reson. Spectrosc. 129, 1–27 (2022),
https://doi.org/10.1016/j.pnmrs.2021.12.001
[20] V. Mazan and M. Boltoeva, Insight into the ionic interactions in neat ionic liquids by diffusion ordered spectroscopy nuclear magnetic resonance, J. Mol. Liq. 240, 74–79 (2017),
https://doi.org/10.1016/j.molliq.2017.05.021
[21] M. Zanatta, V.U. Antunes, C.F. Tormena, J. Dupont, and F.P. Dos Santos, Dealing with supramolecular structure for ionic liquids: A DOSY NMR approach, Phys. Chem. Chem. Phys. 21(5), 2567–2571 (2019),
https://doi.org/10.1039/C8CP07071G
[22] V. Klimavicius, V. Bacevicius, Z. Gdaniec, and V. Balevicius, Pulsed-field gradient 1H NMR study of diffusion and self-aggregation of long-chain imidazolium-based ionic liquids, J. Mol. Liq. 210, 223–226 (2015),
https://doi.org/10.1016/j.molliq.2015.05.034
[23] J. Cascão, W. Silva, A.S.D. Ferreira, and E.J. Cabrita, Ion pair and solvation dynamics of [Bmim][BF4] + water system, Magn. Reson. Chem. 56(2), 127–139 (2018),
https://doi.org/10.1002/mrc.4673
[24] S.U. Rather, H.S. Bamufleh, H. Alhumade, U. Saeed, A.A. Taimoor, A.A. Sulaimon, W.M. Alalayah, and A.M. Shariff, Theoretical and experimental studies of 1-butyl-3-methyl-imidazolium methanesulfonate ionic liquid, Int. J. Energy Res. 2023, 1–10 (2023),
https://doi.org/10.1155/2023/3971296
[25] M. Sieland, M. Schenker, L. Esser, B. Kirchner, and B.M. Smarsly, Ionic liquid-based low-temperature synthesis of crystalline Ti(OH) OF·0.66H2O: Elucidating the molecular reaction steps by NMR spectroscopy and theoretical studies, ACS Omega 7(6), 5350–5365 (2022),
https://doi.org/10.1021/acsomega.1c06534
[26] K. Hayamizu, Y. Aihara, H. Nakagawa, T. Nukuda, and W.S. Price, Ionic conduction and ion diffusion in binary room-temperature ionic liquids composed of [emim][BF4] and LiBF4, J. Phys. Chem. B 108(50), 19527–19532 (2004),
https://doi.org/10.1021/jp0476601
[27] S.H. Chung, R. Lopato, S.G. Greenbaum, H. Shirota, E.W. Castner Jr., and J.F. Wishart, Nuclear magnetic resonance study of the dynamics of imidazolium ionic liquids with –CH2Si(CH3)3 vs –CH2C(CH3)3 substituents, J. Phys. Chem. B 111(18), 4885–4893 (2007),
https://doi.org/10.1021/jp071755w
[28] Iolitec Technical Data Sheet (2025),
https://iolitec.de/index.php/en/downloads/technical-data-sheet
[29] Y. Yoshimura, H. Kimura, C. Okamoto, T. Miyashita, Y. Imai, and H. Abe, Glass transition behaviour of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate–H2O mixed solutions, J. Chem. Thermodyn. 43(3), 410–412 (2011),
https://doi.org/10.1016/j.jct.2010.10.010
[30] H. Tokuda, K. Hayamizu, K. Ishii, M.A.B.H. Susan, and M. Watanabe, Physicochemical properties and structures of room-temperature ionic liquids. 2. Variation of alkyl chain length in imidazolium cation, J. Phys. Chem. B 109(13), 6103–6110 (2005),
https://doi.org/10.1021/jp044626d