Synthesis, characterization and physical properties of novel cholinium-based organic magnetic ionic liquids

In this paper, five novel cholinium-based organic magnetic ionic liquids (MILs) were synthesized. The carbon chain links to the nitrogen atom from cationic nucleus. The MILs were comprehensively identified by FT-IR, HPLC, UV–Vis, 1 H NMR and ESI-MS. The MILs have interesting performance to form aqueous two-phase system and can respond to the external magnetic field after the formation of aqueous two-phase system, which can assists magnetically phase separation. The magnetic susceptibility of the MILs was measured at 298   K. Other physical properties such as conductivities, acidity and density were measured in range of 278.15   K to 323.15   K for further application investigation. Satisfactory results were obtained after the data of physical properties were correlated. Based on the measurements and correlations above, some discussions were carried out, including the ion association and ion diffusion , the influences of MILs carbon chain and temperature on the molar conductivity , the influences of the cation size on the molar volume , acidity variation of the MILs.