An Electrochemical and ESR Spectroscopic Study on the Molecular Dynamics of TEMPO in Room Temperature Ionic Liquid Solvents

Slow rotational diffusion of probe molecule TEMPO in several room temperature ionic liquid solvents results in asymmetry in its ESR spectrum (see figure), the severity of which depends on the temperature. In some cases the observed variation may be rationalised using simple hydrodynamic theories, while in others it points to an increased level of ordering within the liquid structure (TEMPO: 2,2,6,6-tetramethylpiperidine-N-oxyl).