Details

Autor(en) / Beteiligte

• Scharf, Nathan T
• Stark, Annegret
• Hoffmann, Markus M

Titel

Ion Pairing and Dynamics of the Ionic Liquid 1‑Hexyl-3-methylimidazolium Bis(irifluoromethylsulfonyl)amide ([C6mim][NTf2]) in the Low Dielectric Solvent Chloroform

Ist Teil von

• The journal of physical chemistry. B, 2012-09, Vol.116 (37), p.11488-11497

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2012

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The structural and dynamic behavior of the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([C6mim][NTf2]) in chloroform has been studied by experimental measurements of 1H and 19F self-diffusion coefficients, viscosity, and excess molar volume in the concentration range of 0.001–1.0 mol·kg–1 and temperatures ranging from 15 to 45 °C. Within measurement uncertainty, the 1H and 19F self-diffusion coefficients are identical at the same experimental conditions of concentration and temperature, indicating that even to the lowest measured concentrations the cation and anion are not completely dissociated. The combined experimental data indicates a progression from ion pairing to aggregate formation as concentration increases where at concentrations near 0.1 mol·kg–1 aggregate formation becomes dominant. Concurrently with the formation of the IL aggregates at higher concentrations, we also observe an apparent breakdown of the validity of the Stokes–Einstein equation, which we explain by translational motion to become dominated by individual ion pairs moving rapidly between IL aggregates.