Synthesis and Characterization of New Pyrrolidinium Based Protic Ionic Liquids.Good and Superionic Liquids

摘要

New pyrrolidinium-cation-based protic acid ionic liquids(PILs)were prepared through a simple and atom-economic neutralization reactions between pyrrolidine and Br0nsted acids,HX,where X is NO_3~-,HSO_4~-,HCOO~-,CH3COO~-or CF3COO~-and CH3(CH2)6COO~-.The thermal properties,densities,electrochemical windows,temperature dependency of dynamic viscosity and ionic conductivity were measured for these PILs.All protonated pyrrolidinium salts studied here were liquid at room temperature and possess a high ionic conductivity(up to 56 mS cm~(-1))at room temperature.Pyrrolidinium based PILs have a relatively low cost,a low toxicity and exhibit a large electrochemical window as compared to other protic ionic liquids(up 3 V).Obtained results allow us to classify them according to a classical Walden diagram and to determinate their"Fragility".Pyrrolidinium based PILs are good or superionic liquids and shows extremely fragility.They have wide applicable perspectives for fuel cell devices,thermal transfer fluids,and acid-catalyzed reaction media as replacements of conventional inorganic acids.