Diff60 gradient unit

The NMR measurements on a Bruker Avance—III 400 MHz NMR spectrometer equipped with the diff60 gradient unit (the maximum field gradient amplitude was 30 T m⁻¹) were carried out at the temperature 22 ± 1 °C. The NMR measurements of ¹H (diffusion of solvent molecules EC and ionic liquid IL, EMI⁻), ⁷Li (diffusion of lithium cations) and ¹⁹F (diffusion of anions BF₄⁻) were carried out with operating frequencies of 400, 155.5 and 376.5 MHz, respectively. The stimulated spin echo sequence was applied. The details of self-diffusion coefficient measurements are given in [31 (link),32 (link)]. The experimental NMR parameters of pulse sequences were the following: π/2 pulse was 9 μs (¹H), 9 μs (⁷Li) and 10 μs (¹⁹F); gradient pulse duration time δ was 1.0 (¹H), 1.0 (⁷Li) and 3.0 (¹⁹F) ms; diffusion time was 19.7 (¹H), 19.7 (⁷Li) and 49.0 (¹⁹F) ms; repetition time 3 s; and the diffusion 32 steps with maximum field gradient amplitude g were 3.5 (¹H), 11.5 (⁷Li) and 4.0 (19F) T m⁻¹. The strength of the gradient changed linearly. The measurement error of the self-diffusion coefficients was 5%. The temperature dependences of the diffusion coefficients were measured at the temperature range from 22 to 60 °C.

The NMR measurements on a Bruker Avance-III 400 MHz NMR spectrometer equipped with the diff60 gradient unit (the maximum field gradient amplitude was 30 T/m) were carried out at the temperature 22 ± 1 °C. The NMR measurements of ¹H (diffusion of solvent molecules), ⁷Li (diffusion of lithium cations), and ¹⁹F (diffusion of anions) were carried out with operating frequencies of 400, 155.5, and 376.5 MHz, respectively. The stimulated spin-echo sequence was applied. The details of self-diffusion coefficient measurements are given in [61 (link),62 (link)]. The experimental NMR parameters of pulse sequences were the following: π/2 pulse was9.5 μs (¹H), 9 μs (⁷Li), and 10 μs (¹⁹F); gradient pulse duration time δ was 1–1.5 ms; and the diffusion 32 steps with maximum field gradient amplitude g were 3.5 (¹H), 11.5 (⁷Li), and 4.0 (¹⁹F) T/m. The measurement error of the self-diffusion coefficients was 5%.