Liquid Ordering Structure in Binary Room Temperature Ionic Liquids Based on Aliphatic Quaternary Ammonium Ions

摘要

The effects of hetero-species on the local ordering structure composed of AQA cation are discussed with alkali metal- and alkali earth metal cations (Li{sup}+, Na{sup}+, K{sup}+, Rb{sup}+, Cs{sup}+, Mg{sup}(2+), Ca{sup}(2+), Sr{sup}(2+), and Ba{sup}(2+)) as hetero-species, taking into account the difference of ionic potential of metal cations. The effects of secondary cationic species on the ordering structure in ILs are discussed. Binary ILs refer to mixture of N111,8[TFSI] and M[TFSI]{sub}z (M=Li{sup}+, Na{sup}+, K{sup}+, Rb{sup}+, Cs{sup}+, Mg{sup}(2+), Ca{sup}(2+), Sr{sup}(2+), Ba{sup}(2+)) in an appropriate molar ratio (x=0.1, 0.2, 0.3, 0.5, z=1, 2), denoted as M{sub}xN111,8{sub}(1-x)[TFSI]{sub}({1+(z-1)x}). From the results of SAXS and WAXS measurement of M{sub}xN111,8{sub}(1-x) [TFSI]{sub}({1+(z-1)x}), the intensity assigned to ordering structure increases with addition of M[TFSI]{sub}z and, is higher in mixed with alkali earth metal cation than alkali metal cation. Cationic structural ordering is enhanced by the effects of added metal cation.