Conductivity of N-(2-methoxyethyl)-substituted morpholinium- and piperidinium-based ionic liquids and their acetonitrile solutions

Abstract

N-ethyl-N-(2-methoxyethyl)-morpholinium bis(trifluoromethylsulfonyl)imide [Et(MEO)Mor][TFSI], N,N-bis(2-methoxyethyl)-morpholinium bis(trifluoromethylsulfonyl)imide [Bis(MEO)Mor][TFSI] and N,N-bis(2-methoxyethyl)-piperidinium bis(trifluoromethylsulfonyl)imide [Bis(MEO)Pip][TFSI] room-temperature ionic liquids (RTILs) were synthesized and their electrochemical properties were studied. Three stages of synthesis of RTILs were used, including the alkylation of secondary and tertiary amines and the anion exchange. The structure of RTILs was confirmed by 1H, [Formula: see text]C, H,H-COSY, 1H–[Formula: see text]C correlation spectroscopy NMR and XPS. Three main approaches based on the Arrhenius, Litovitz, and Vogel–Fulcher–Tammann equations were used to analyze the ion transport properties of RTILs. In addition, the electrical conductivity of the binary acetonitrile solutions of RTILs was studied. It was found that the activation energy and conductivity of RTILs depended on their polarity and ability to associate which affects the mobility of charge carriers and viscosity of the system.