An ionic liquid, ,,-trimethyl--propylammonium bis(trifluoromethanesulfonyl)imide (TMPA TFSI), was transformed from a liquid phase to another fluidic phase by application of the threshold magnetic field at constant temperature (). The magnetic-field-induced (MFI) phase transformation was detected by the electric potential generated between two Pt electrodes set to the bottom and upper parts in a TMPA TFSI liquid during sweep of the magnetic field (). The magnetic susceptibility and Verdet constant of TMPA TFSI also were slightly changed over 3 T. The MFI phase formation was almost completed within 3 h after TMPA TFSI liquid was exposed to a 6 T magnetic field, as demonstrated by the melting behavior of TMPA TFSI solid frozen instantaneously under 6 T. Multivariate analysis of the Raman spectra suggested that the MFI transformation should be associated with the conformational change of the transoid-to-cisoidlike species of TFSI ions. A - phase diagram of TMPA TFSI is proposed.
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http://dx.doi.org/10.1021/acs.jpclett.9b03217 | DOI Listing |
RSC Adv
May 2023
State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, College of Energy Engineering, Zhejiang University Hangzhou 310027 Zhejiang China
Supercapacitors with high energy and power densities have become highly desirable in practical applications. Ionic liquids (ILs) are considered as promising electrolytes of supercapacitors owing to their excellent electrochemical stability window (approx. 4-6 V) and good thermal stability.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2020
Department of Chemistry, Faculty of Science , Shinshu University, 3-1-1 Asahi , Matsumoto , Nagano 390-8621 , Japan.
An ionic liquid, ,,-trimethyl--propylammonium bis(trifluoromethanesulfonyl)imide (TMPA TFSI), was transformed from a liquid phase to another fluidic phase by application of the threshold magnetic field at constant temperature (). The magnetic-field-induced (MFI) phase transformation was detected by the electric potential generated between two Pt electrodes set to the bottom and upper parts in a TMPA TFSI liquid during sweep of the magnetic field (). The magnetic susceptibility and Verdet constant of TMPA TFSI also were slightly changed over 3 T.
View Article and Find Full Text PDFChemphyschem
October 2018
Istituto dei Sistemi Complessi, U.O.S. La Sapienza, Consiglio Nazionale delle Ricerche, Piazzale A. Moro 5, I-00185, Roma, Italy.
The X-ray scattering patterns of the two ionic liquids, N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide (TMPA-TFSI) and N-trimethyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide (TMHA-TFSI), sharing a common anion and differing in the length of the alkyl chain of the cation, were measured at room temperature. Molecular dynamics calculations supported the interpretation of the data. The two force-field models, GAFF and DLPOLY 4, were adopted to simulate the scattering patterns.
View Article and Find Full Text PDFPhys Chem Chem Phys
March 2017
CNR-ISC, U.O.S. La Sapienza, Piazzale A. Moro 5, 00185 Roma, Italy.
A detailed investigation of the phase diagram of the mixtures of the two ionic liquids N-trimethyl-N-propylammonium bis(trifluoromethylsulfonyl)imide (TMPA-TFSI) and N-trimethyl-N-hexylammonium bis(trifluoromethylsulfonyl)imide (TMHA-TFSI) has been performed in the temperature range between 140 and 330 K by means of DSC and infrared spectroscopy measurements. In the low temperature crystalline states, a large concentration of the trans-TFSI conformer is present in TMPA-TFSI, while almost only cis-TFSI is retained in TMHA-TFSI. For the mixtures (TMPA-TFSI) (TMHA-TFSI), at concentrations close to the extremes, solid crystalline phases are still present and they show a strong predominance of the trans conformer of the TFSI ion for x < 15 or a large concentration of the cis conformer of TFSI for x > 85.
View Article and Find Full Text PDFJ Phys Chem B
February 2016
CNR-ISC, U.O.S. La Sapienza , Piazzale A. Moro 5, 00185 Roma, Italy.
Absorbance spectra of two ionic liquids, the short alkyl chain N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide (TMPA-TFSI) and the longer chain N-trimethyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide (TMHA-TFSI) are reported as a function of pressure and temperature. The occurrence of various phase transitions is evidenced by the changes in the relative concentration of the cisoid and transoid conformers of their common TFSI anion. The infrared spectrum of TMPA-TFSI was measured at 300 K with an applied pressure varying over the 0-5 GPa range.
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