Microscopic Diffusion Dynamics of Silver Complex‐Based Room‐Temperature Ionic Liquids Probed by Quasielastic Neutron Scattering

Mamontov, Eugene; Baker, Gary A.; Luo, Huimin; Dai, Sheng

doi:10.1002/cphc.201001017

Cited by 34 publications

(37 citation statements)

References 34 publications

(48 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, a linear dependence of drift time on the mass of the IL aggregates indicates an abnormally high mobility for bulkier cations of the ILs. 123,124 Atmospheric-pressure chemical ionization mass spectrometry is also used to detect the presence of IL aggregates by transferring species from the condensed phase to the gas phase, and some neutral clusters of the type [DAI.X] n (n = 1, 2, and 3) have been observed. 125 Electric conductivity, NMR, ESI-MS and IR data also support the presence of larger neutral and charged aggregates, even when dissolved in solvents with relatively high dielectric constants, such as acetonitrile and dimethyl sulfoxide (DMSO).…”

Section: H-bonding Network Ionic Aggregate and Assemblymentioning

confidence: 99%

Understanding the hydrogen bonds in ionic liquids and their roles in properties and reactions

2016

View full text Add to dashboard Cite

Ionic liquids (ILs) have many potential applications in the chemical industry. In order to understand ILs, their molecular details have been extensively investigated. Intuitively, electrostatic forces are solely important in ILs. However, experiments and calculations have provided strong evidence for the existence of H-bonds in ILs and their roles in the properties and applications of ILs. As a structure-directing force, H-bonds are responsible for ionic pairing, stacking and self-assembling. Their geometric structure, interaction energy and electronic configuration in the ion-pairs of imidazolium-based ILs and protic ionic liquids (PILs) show a great number of differences compared to conventional H-bonds. In particular, their cooperation with electrostatic, dispersion and π interactions embodies the physical nature of H-bonds in ILs, which anomalously influences their properties, leading to a decrease in their melting points and viscosities and thus fluidizing them. Using ILs as catalysts and solvents, many reactions can be activated by the presence of H-bonds, which reduce the reaction barriers and stabilize the transition states. In the dissolution of lignocellulosic biomass by ILs, H-bonds exhibit a most important role in disrupting the H-bonding network of cellulose and controlling microscopic ordering into domains. In this article, a critical review is presented regarding the structural features of H-bonds in ILs and PILs, the correlation between H-bonds and the properties of ILs, and the roles of H-bonds in typical reactions.

show abstract

Section: H-bonding Network Ionic Aggregate and Assemblymentioning

confidence: 99%

Understanding the hydrogen bonds in ionic liquids and their roles in properties and reactions

2016

View full text Add to dashboard Cite

show abstract

“…Firstly, it accounts for the fact, known from MD simulations, that the b-fast dynamic component in water is not strictly rotational, but involves motions of the molecular center of mass instead. Secondly, this ''basin'' description was found generally applicable to the liquid state of glass-forming fluids in general, from room-temperature ionic liquids [23][24][25][26] to molecular glass-formers and molten single-element compounds. 27 In the language of glass physics and the mode-coupling theory (MCT), 28 the ''intra-basin'' component represents b-relaxation.…”

Section: Introductionmentioning

confidence: 97%

Water–protein dynamic coupling and new opportunities for probing it at low to physiological temperatures in aqueous solutions

Mamontov

Chu

2012

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

Both the structure and dynamics of biomolecules are known to be essential for their biological function. In the dehydrated state, the function of biomolecules, such as proteins, is severely impeded, so hydration is required for bioactivity. The dynamics of the hydrated biomolecules and their hydration water are related - but how closely? The problem involves several layers of complexity. Even for water in the bulk state, the contribution from various dynamic components to the overall dynamics is not fully understood. In biological systems, the effects of confinement on the hydration water further complicate the picture. Even if the various components of the hydration water dynamics are properly understood, which of them are coupled to the protein dynamics, and how? The studies of protein dynamics over the wide temperature range, from physiological to low temperatures, provide some answers to these question. At low temperatures, both the protein and its hydration water behave as solids, with only vibrational degrees of freedom. As the temperature is increased, non-vibrational dynamic components start contributing to the measurable dynamics and eventually become dominant at physiological temperatures. Thus, the temperature dependence of the dynamics of protein and its hydration water may allow probing various dynamic components separately. In order to suppress the water freezing, the low-temperature studies of protein rely on either low-hydrated samples (essentially, hydrated protein powders), or cryo-protective solutions. Both approaches introduce the hydration environments not characteristic of the protein environments in living systems, which are typically aqueous protein solutions of various concentrations. In this paper, we discuss the coupling between the dynamic components of the protein and its hydration water by critical examining of the existing literature, and then propose that proteins can be studied in an aqueous solution that is remarkably similar in its dynamic properties to pure water, yet does not freeze down to about 200 K, even in the bulk form. The first experiment of this kind using quasielastic neutron scattering is discussed, and more experiments are proposed.

show abstract

“…[10][11][12][13] Additionally, QENS allows one to obtain spacial characteristics of observed processes, such as radii of confinement, correlation lengths or jump distances, because typical wavelengths of incident neutrons are of the order of interatomic distances in solids and liquids. Being particularly sensitive to hydrogen atoms, incoherent neutron spectroscopy is beneficial in investigating dynamical processes in hydrogen-rich materials, to which ILs can be ascribed as well, [14][15][16][17] and finally could be applied to obtain information on proton diffusivity in PILs. 18,19 The objective of our work was to employ QENS and deuterium labelling to explore transport properties in triethylammonium triflate (TEA-TF).…”

Section: Introductionmentioning

confidence: 99%

Proton Diffusivity in the Protic Ionic Liquid Triethylammonium Triflate Probed by Quasielastic Neutron Scattering

et al. 2015

View full text Add to dashboard Cite

Quasielastic neutron scattering (QENS) in combination with deuterium labeling allows for studying protonated "highlighted" species and extracting detailed information about tangled stochastic processes. This approach has been applied to examine proton dynamics in the protic ionic liquid, triethylammonium triflate. The temperature range covered during the experiments (2-440 K) included two melting transitions correspondingly reflected in the global and localized dynamics of the cation. To focus on the dynamics of the acidic proton, QENS spectra of the sample with the deuterated alkyl side chains were analyzed. The remaining hydrogen atom served as a tagged particle for investigating both global long-range motion of the cation and specific dynamics of the proton and, thus, provided insight into the transport properties of triethylammonium triflate, which is important for designing electrochemical devices.

show abstract

Microscopic Diffusion Dynamics of Silver Complex‐Based Room‐Temperature Ionic Liquids Probed by Quasielastic Neutron Scattering

Cited by 34 publications

References 34 publications

Understanding the hydrogen bonds in ionic liquids and their roles in properties and reactions

Understanding the hydrogen bonds in ionic liquids and their roles in properties and reactions

Water–protein dynamic coupling and new opportunities for probing it at low to physiological temperatures in aqueous solutions

Proton Diffusivity in the Protic Ionic Liquid Triethylammonium Triflate Probed by Quasielastic Neutron Scattering

Contact Info

Product

Resources

About