Bis-methyl imidazolium methylidene bis(trifluoromethanesulfonyl)imide, crystal structure, thermal and dielectric studies

A new geminal di-cationic ionic liquid (IL) containing a central cationic unit methylidene capped by a basic functionality (imidazole) is synthesized. The compound was characterized by means of1H,13C,19F NMR, IR and Raman spectroscopies and its crystal structure is confirmed by single crystal X-ray diffraction method. The X-ray studies on ([M(CH2)IM2+][2NTf $₂^-$ ]) show that it crystallizes in monoclinic system with space group: P 21/c. Thermal properties were investigated in the temperature range from 0 to 400∘C by using differential thermal (DTA) and thermogravimetric (TGA) analyses. The frequency-dependent electrical data are discussed using complex dielectric permittivity in the frequency range of (10−2–106 Hz) and in the temperature range of −50∘ to 20∘C. The outstanding dielectric and thermal properties make this IL as promising candidate for electrochemical devices.