Synthesis And Structure-Activity Relationship Of Imidazolium Ionic Liquids

The materials which are liquid state at a room temperature or near the room temperature are named room-temperature ionic liaquids(RTILs) or room temperature molten salts.The RTILs is the perfect substitute of conventional solvents owing to its highly conductivity,wide electrochemical widow,neglectable vapor tension and adjustable acidity and amenable to diverse solutes.The study of RTILs accord with the development of green chemistry,and are paid great attention to by the researchers in world in recent years.A series of room temperature ionic liquids based on seven 1-alkyl-3-methy-limidazolium bromides([C_2-8MIm]Br),seven 1-alkyl-3-methylimidazolium tetrafluoroborate([C_2-8MIm]BF₄),chloride([C₄MIm]Cl),iodide([C₄MIm]I) and[C₄MIm]PF₆ were synthesized,and the compounds were characterized by IR,MS and ¹H NMR,¹³C NMR,whose structures were comfirmed.Density and surface tensions were measured using a Wilhelmy plate apparatus in 25℃.We also researched the structure-activity relationship of imidazolium ionic liquids.The result shows that density and surface tensions of ionic liquids bromides and tetrafluoroborate decreased with the length of alkyl chain on the cation increased.The range of density and surface tensions of imidazolium ionic liquids who has same cation and different anion is large,the larger is the m/v,the larger is the density;The larger is the quality of anion,the larger is the surface tensions.