Solvate and protic ionic liquids from aza-crown ethers: synthesis, thermal properties, and LCST behavior

摘要: In recent years, solvate and protic ionic liquids (ILs) have attracted much attention. We synthesized both types of ILs from alkyl aza-crown ethers (L = N-propyl-1-aza-15-crown-5 (L1) N-C6F13C2H4-1-aza-15-crown-5 (L2)). The [ML][Tf2N] (M Na+, K+) were solids (Tm 58–68 °C), whereas the Li+, Ag+) [HL][Tf2N] with low glass transition temperatures. containing Na ions more crystalline exhibited higher melting points than other ILs. decomposition temperatures those A IL a paramagnetic anion, [HL1][FeCl4] 70.5 was also its crystal structure determined. [NaL2][X] (X Cl−, CF3CO2−, TsO−, PhSO3−) lower critical solution temperature (LCST)-type behavior in water. effects salt addition on LCST L2 investigated. these generally increased increasing hydrophilicity or basicity counter anion. This tendency, which is nearly opposite to that quaternary onium cations, ascribed amphiphilic nature cation. corresponding did not exhibit behavior.