Triethanolamine-based protic ionic liquids with various sulfonic acids: Synthesis and properties

摘要

Abstract Ten tris(2-hydroxyethyl)ammonium (triethanolammonium)-based protic ionic liquids (ILs) and one molten salt were synthesized by proton transfer reaction from sulfonic acid to triethanolamine (TEOA). The produced PILs were dried under high vacuum at 50°C for 8h before use. The PILs were characterized by 1H NMR, 13C NMR, 1H/15N NMR and FT-IR spectroscopic methods. The parameters of IR and NMR spectra of the studied PILs were determined by the nature of the substituent on the sulfonic acid benzene ring. The phase behavior of the PILs was studied using differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA). The temperature dependence of the conductivity and the electrochemical window of each PIL was investigated. The substitution effect on the PILs anionic component was discussed for the studied properties. Graphical abstract Display Omitted Highlights ? Protic ionic liquids based on triethanolamine with sulfonic acids were synthesized. ? The PILs were characterized by NMR and FT-IR spectroscopic methods. ? The phase behavior of the PILs using DSC and TGA was studied. ? The conductivity of salts are within the range of 10?5 ÷10?3 Ω?1·cm?1. ? The electrochemical window of PILs at 120°С lies within the range of 2.9–4.5V. ]]>