Lithium transport in a macrocyclic electrolyte

Hole-burning diffusion measurements in high magnetic field gradients

“…Recent work on 3-dimensional NMR microimaging with applied gradients of 50 T/m have successfully achieved voxel volume resolution of 40 femtoliters for biological cell imaging. (5,6) Another source of large gradients are those in the fringe fields of NMR magnets (7,8). For common superconducting magnets, such gradients are often in the range of 50 T/m; for high-field resistive magnets (H 0 ≈ 30 T) such as at the National High Magnetic Field Laboratory, fringe field gradients greater than 200 T/m exist.…”

Alkali ion–cryptand interactions and their effects on electrolyte conductivity

“…5 The molecular structure of the pure crystalline phase of LiMPSA was obtained by X-ray diffraction analysis. 5 In order to better understand the mechanism of Li + conductance, NMR analyses were made on 7 Li, 1 H, and 19 F to determine diffusion coefficients of different components of the material. 19 Surprisingly, the diffusion rates of all components were found to be very similar.…”

“…5 In order to better understand the mechanism of Li + conductance, NMR analyses were made on 7 Li, 1 H, and 19 F to determine diffusion coefficients of different components of the material. 19 Surprisingly, the diffusion rates of all components were found to be very similar. By comparing the diffusion coefficients with Tdependent AC conductivity, a model was suggested in which the cation jumps back and forth between C222 and the MPSA anion, spending about 25% of the time complexed with C222.…”

“…The cation density of the C222:LiMPSA samples used in NMR diffusion measurements 19 was r ¼ 1.2 Â 10 21 cm À3 , which corresponds to a mean distance of 8.1 A ˚between CM of C222 and MPSA molecules. Therefore, we chose to constrain further ' gas phase ' simulations so that the CM-CM distance was less than 8 A ˚, determining the radial distribution functions as described above.…”

“…Fringe-field gradient NMR measurements were made on 19 F, protons, and 7 Li to determine the diffusion coefficients of MPSA, Li, and MPSA respectively. Surprisingly, all three components have nearly the same diffusion rate at a given temperature.…”