TY  - JOUR
A1  - Stoesser, Reinhard
A1  - Herrmann, Werner
A1  - Zehl, Andreas
A1  - Strehmel, Veronika
A1  - Laschewsky, André
T1  - ESR spin probes in ionic liquids
N2  - The spin probes 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL), and 2,2,6,6-tetramethyl-4-trimethylammoniumpiperidine-1-oxyllodide (CAT-1) are examined in a number of ionic liquids based on substituted imidazolium cations and tetrafluoroborate and hexafluorophosphate anions, respectively. The reorientation correlation times tau(R) of the spin probes in these systems have been determined by complete spectra simulation and, for rapid reortientation, by analysis of the intensities of the hyperfine lines of the electron spin resonance (ESR) spectra. A comparison of the results with those from the model system glycerol/water and selected organic solvents is made. Additions of diamagnetic and paramagnetic ions allow the conclusion that salt effects and spin exchange are present, and that both are superimposed by motional effects. Specific interactions in the ionic liquids, as well as between the spin-probe molecules and the constituents of the ionic liquids are reflected in the spectra of the spin probes, depending on their molecular structure
Y1  - 2006
UR  - http://onlinelibrary.wiley.com/doi/10.1002/cphc.200500651/full
U6  - https://doi.org/10.1002/cphc.200500651
ER  -