1H NMR study on reorientational dynamics of an ionic liquid, 1-butyl-3-methylimidazolium bromide, accompanied with phase transitions

A review of NMR methods used in the study of the structure and dynamics of ionic liquids

“…Si‐atom substitution in the IL shifts the T 1, min to lower temperature regime indicating a higher rotational motion of the Si‐substituted neopentyl group as compared with the C‐substituted neopentyl group . Imanari et al . observed the coagulated state of the [BMIM][Br] for the first time by the study of T 1 /T 2 relaxation times.…”

“…observed the coagulated state of the [BMIM][Br] for the first time by the study of T 1 /T 2 relaxation times. The T 2 relaxation study shows that the slow reorientational molecular motion of the [BMIM] + cation begin near to their crystallization point . Giernoth et al .…”

High-pressure phase behavior of the room temperature ionic liquid 1-ethyl-3-methylimidazolium nitrate

“…Room temperature ionic liquids (RTILs), which typically consist of organic cations and inorganic anions exhibit many attractive properties [1,2] and unique phase behaviors [3][4][5]. RTILs remain liquid over a wide temperature range at ambient pressure but readily achieve their glassy state when supercooled below their melting points [6][7][8].…”

Characterization of the molecular reorientational dynamics of the neat ionic liquid 1‐butyl‐3‐methylimidazolium bromide in the super cooled state using 1H and 13C NMR spectroscopy

“…In the cooling process of the [bmim]Br observed using DSC, no thermal changes, that is neither exothermic nor endothermic changes, were observed; meanwhile the [bmim]Br changed from the super cooled state to the solid state at ca 273 K. In the heating process, however, both exo-and endothermic signals were clearly observed in the DSC measurements. [3] In the previous study, the 1 H longitudinal and transverse relaxation times (T 1 and T 2 ) were measured as a function of temperature using the 1 H pulse NMR spectroscopy with the 1 H resonance frequency of 25 MHz, [4] and the very slow reorientational molecular motions of the overall [bmim] + were characterized.…”