In prior research, long-lived ion-pairing of the Ionic Liquid (IL) 1-ethyl-3-methyl-imidazolium bis(trifyl)amide (1) has been observed in chloroform as evidenced by two sets of resonances in the 1H spectrum (J. Sol. Chem. Vol. 33, 2004, 381-394). This study focuses on 1-hexyl-3-methylimidazolium bis(trifyl)amide (2) that contains a longer side chain and does not exhibit two resonance sets. The objective of this study was to determine if ion pairing was still present in chloroform solutions of (2) despite only having one 1H NMR resonance set. Therefore, we explored the effect of temperature and concentration on the self-diffusion coefficients of cation and anion measured by 1H and 19F Diffusion Ordered Spectroscopy (DOSY). Viscosity measurements are also obtained to use the Stokes-Einstein relation to determine the effects of temperature and concentration on the effective radius size of the species in solution. Experimental results clearly indicate the formation of ion-pairs and higher aggregates.
|Presenter:||Nathan Scharf (Undergraduate Student)|
|Time:||11 am Session II|