Synthesis, Differential Scanning Calorimetry (DSC) and Dielectric Relaxation Spectroscopy (DRS) Studies of N-methyl-N-propylpiperidinium Bis(trifluoromethylsulfonyl)imide

Ionic liquid based on N-methyl-N-propylpiperidinium [MPrPPI+] cation and bis(trifluoromethanesulfonyl) imide [TFSI-] anion has been synthesized and characterized. The synthesis is based on alkylation reaction of N-methylpiperidine followed by anion exchange. The structure of [MPrPPI^][TFSI_] was identified by using :H, 13C, 19F NMR and FT-IR spectroscopy. The phase behavior change for [MPrPPI+][TFSI-] was measured in the temperature range from -150 to 200 °C by using differential scanning calorimetry (DSC). In the frequency 10-2 - 106 Hz range, dielectric measurements were performed on IL sample at various temperatures from -69 to -19 °C, i.e. around the glass transition temperature. The peak relaxation was observed near to this temperature. Also, in order to understand the ion dynamics in our IL, the frequency dependence of the complex conductivity (aʹ, aʹʹ) of [MPrPPI+][TFSI-] at various temperatures has been analyzed. The relaxation has been characterized by the empirical Havriliak-Negami (H-N) equation.