NMR Relaxation and Self-Diffusion Study at High and Low Magnetic Fields of Ionic Association in Protic Ionic Liquids
Geoffrey L Burrell, Iko M Burgar, Qingxia Gong, Noel F Dunlop, Frances Separovic
JOURNAL OF PHYSICAL CHEMISTRY B | AMER CHEMICAL SOC | Published : 2010
NMR relaxation and diffusion characterization of several protic ionic liquids at high and low magnetic fields are reported. The dynamics of cations and anions were similar at both frequencies, with similar trends and magnitudes for a fixed component paired with oppositely charged species. An Arrhenius relationship was displayed between the molecular motion and the glass transition temperature. The diffusion of ions showed a strong degree of ion correlation between cation and anion, and Arrhenius plots of relaxation and diffusion indicated that the ions diffused as a pair. At high field diffusion was dominated by mobile species that followed Stokes-Einstein behavior. Conversely, diffusion obs..View full abstract
Awarded by ARC
This work was supported by an ARC Linkage grant (LP0668123). We thank Prof. Bernhard Blumich (RWTH-Aachen) and Prof. William Price (University of Western Sydney) for instrument time and helpful discussions.