Current location: JICS Archive > Vol. 8 > No. 1 > Articles : 15

Synthesis and Characterization of Protic Ionic liquids Containing Cyclic Amine Cations and Tetrafluoroborate Anion

T.Y. Wu^a,b, S.G. Su^a, S.T. Gung^a, M.W. Lin^a, Y.C. Lin^c, W.C. Ou-Yang^d, I.W. Sun^a,e,* and C.A. Lai^a

^aDepartment of Chemistry, National Cheng Kung University, Tainan, Taiwan
^bDepartment of Polymer Materials, Kun Shan University, Tainan 71003, Taiwan
^cInstitute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
^dDepartment of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan
^eSustainable Environment Research Center, National Cheng Kung University, Tainan 701, Taiwan

Several ionic liquids containing pyrrolidinium-, oxopyrrolidinium-, piperidinium-, morpholinium- and trialkylammonium-based cation are synthesized and their thermal property, refractive index, polarity, electrochemical property, and temperature dependency of dynamic viscosity, density and ionic conductivity are characterized. All tetrafluoroborate-based room temperature ionic liquids studied here have a high ionic conductivity (up to 31.4 mS cm^-1). These ILs were successfully used as suitable electrolytes for the diffusion coefficient measurement of ferrocene. Absorbance solvatochromic probes Nile red is used to investigate the relative polarity of these ionic liquids and compared them with several organic solvents. The relation of fluidity to conductance is considered in terms of a Walden plot that is shown to provide a useful basis for organizing the applications of solvent media for “green” synthetic reactions.

Keywords: Ionic liquid, Oxopyrrolidinium, Potential window, Diffusion coefficient, Conductivity, Polarity