@article{WojnarowskaLangeTaubertetal.2021, author = {Wojnarowska, Zaneta and Lange, Alyna and Taubert, Andreas and Paluch, Marian}, title = {Ion and proton transport in aqueous/nonaqueous acidic tonic liquids for fuel-cell applications-insight from high-pressure dielectric studies}, series = {ACS applied materials \& interfaces / American Chemical Society}, volume = {13}, journal = {ACS applied materials \& interfaces / American Chemical Society}, number = {26}, publisher = {American Chemical Society}, address = {Washington}, issn = {1944-8244}, doi = {10.1021/acsami.1c06260}, pages = {30614 -- 30624}, year = {2021}, abstract = {The use of acidic ionic liquids and solids as electrolytes in fuel cells is an emerging field due to their efficient proton conductivity and good thermal stability. Despite multiple reports describing conducting properties of acidic ILs, little is known on the charge-transport mechanism in the vicinity of liquid-glass transition and the structural factors governing the proton hopping. To address these issues, we studied two acidic imidazolium-based ILs with the same cation, however, different anions-bulk tosylate vs small methanesulfonate. High-pressure dielectric studies of anhydrous and water-saturated materials performed in the close vicinity of T-g have revealed significant differences in the charge-transport mechanism in these two systems being undetectable at ambient conditions. Thereby, we demonstrated the effect of molecular architecture on proton hopping, being crucial in the potential electrochemical applications of acidic ILs.}, language = {en} } @article{BauerHartmannKleinpeteretal.2015, author = {Bauer, Monika and Hartmann, Lutz and Kleinpeter, Erich and Kuschel, Frank and Pithart, Cornelia and Weissflog, Wolfgang}, title = {Chiral Dopants Derived from Ephedrine/Pseudoephedrine: Structure and Medium Effects on the Helical Twisting Power}, series = {Molecular crystals and liquid crystals}, volume = {608}, journal = {Molecular crystals and liquid crystals}, number = {1}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {1542-1406}, doi = {10.1080/15421406.2014.949592}, pages = {14 -- 24}, year = {2015}, abstract = {Chiral dopants were obtained by acylation of enantiomerically pure ephedrine and pseudoephedrine with promesogenic carbonyl reagents. The products have been investigated with respect to their chiral transfer ability on nematic host matrices characterized by extreme differences of the dielectric anisotropy. It has been found that the medium dependence of the helicity induction nearly disappears at reduced temperatures. Based on variable temperature H-1 NMR studies on monoacylated homologues, the estimated coalescence temperatures and free activation enthalpies for the hindered rotation around C-N bonds could be correlated with the helical twisting power. Measurements by dielectric spectroscopy reveal the correlation between the molar mass of substituents linked to the chiral building block and the dynamic glass transition of corresponding chiral dopants. Furthermore, the effect of intramolecular and intermolecular hydrogen bonds has been studied by ATR-FTIR spectroscopy.}, language = {en} }