Browse
Submit Data
Databases
API
Help

Dataset Information

46 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Ion clustering in aqueous solutions probed with vibrational energy transfer

ABSTRACT: Despite prolonged scientific efforts to unravel the hydration structures of ions in water, many open questions remain, in particular concerning the existences and structures of ion clusters in 1∶1 strong electrolyte aqueous solutions. A combined ultrafast 2D IR and pump/probe study through vibrational energy transfers directly observes ion clustering in aqueous solutions of LiSCN, NaSCN, KSCN and CsSCN. In a near saturated KSCN aqueous solution (water/KSCN molar ratio = 2.4/1), 95% of the anions form ion clusters. Diluting the solution results in fewer, smaller, and tighter clusters. Cations have significant effects on cluster formation. A small cation results in smaller and fewer clusters. The vibrational energy transfer method holds promise for studying a wide variety of other fast short-range molecular interactions.

SUBMITTER: Bian H

PROVIDER: S-EPMC3064342 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Quantifying Interfacial Ion Transfer at Operating Potassium-Insertion Battery Electrodes within Highly Concentrated Aqueous Solutions.

Project description:Electrode/electrolyte interfacial ion transfer is a fundamental process occurring during insertion-type redox reactions at battery electrodes. The rate at which ions move into and out of the electrode, as well as at interphase structures, directly impacts the power performance of the battery. However, measuring and quantifying these ion transfer phenomena can be difficult, especially at high electrolyte concentrations as found in batteries. Herein, we report a scanning electrochemical microscope method using a common ferri/ferrocyanide (FeCN) redox mediator dissolved in an aqueous electrolyte to track changes in alkali ions at high electrolyte concentrations (up to 3 mol dm-3). Using voltammetry at a platinum microelectrode, we observed a reversible E1/2 shift of ∼60 mV per decade change in K+ concentrations. The response showed high stability in sequential measurements and similar behavior in other aqueous electrolytes. From there, we used the same FeCN mediator to position the microelectrode at the surface of a potassium-insertion electrode. We demonstrate tracking of local changes in the K+ concentration during insertion and deinsertion processes. Using a 2D axisymmetric, finite element model, we further estimate the effective insertion rates. These developments enable characterization of a key parameter for improving batteries, the interfacial ion transfer kinetics, and future work may show mediators appropriate for molar concentrations in nonaqueous electrolytes and beyond.

| S-EPMC11231980 | biostudies-literature

Molecular Dynamics Investigation of Clustering in Aqueous Glycine Solutions.

Project description:Recent experiments with undersaturated aqueous glycine solutions have repeatedly exhibited the presence of giant liquid-like clusters or nanodroplets around 100 nm in diameter. These nanodroplets re-appear even after careful efforts for their removal and purification of the glycine solution. The composition of these clusters is not clear, although it has been suggested that they are mainly composed of glycine, a small and very soluble amino acid. To gain insights into this phenomenon, we study the aggregation of glycine in aqueous solutions at concentrations below the experimental solubility limit using large-scale molecular dynamics simulations under ambient conditions. Three protonation states of glycine (zwitterion = GLZ, anion = GLA, and cation = GLC) are simulated using molecular force fields based on the 1.14*CM1A partial charge scheme, which incorporates the OPLS all-atom force field and TIP3P water. When initiated from dispersed states, we find that giant clusters do not form in our simulations unless salt impurities are present. Moreover, if simulations are initiated from giant cluster states, we find that they tend to dissolve in the absence of salt impurities. Therefore, the simulation results provide little support for the possibility that the giant clusters seen in experiments are composed purely of glycine (and water). Considering that strenuous efforts are made in experiments to remove impurities such as salt, we propose that the giant clusters observed might instead result from the aggregation of reaction products of aqueous glycine, such as diketopiperazine or other oligoglycines which may be difficult to separate from glycine using conventional methods, or their co-aggregation with glycine.

| S-EPMC9251761 | biostudies-literature

Femtosecond proton transfer in urea solutions probed by X-ray spectroscopy.

Project description:Proton transfer is one of the most fundamental events in aqueous-phase chemistry and an emblematic case of coupled ultrafast electronic and structural dynamics1,2. Disentangling electronic and nuclear dynamics on the femtosecond timescales remains a formidable challenge, especially in the liquid phase, the natural environment of biochemical processes. Here we exploit the unique features of table-top water-window X-ray absorption spectroscopy3-6 to reveal femtosecond proton-transfer dynamics in ionized urea dimers in aqueous solution. Harnessing the element specificity and the site selectivity of X-ray absorption spectroscopy with the aid of ab initio quantum-mechanical and molecular-mechanics calculations, we show how, in addition to the proton transfer, the subsequent rearrangement of the urea dimer and the associated change of the electronic structure can be identified with site selectivity. These results establish the considerable potential of flat-jet, table-top X-ray absorption spectroscopy7,8 in elucidating solution-phase ultrafast dynamics in biomolecular systems.

| S-EPMC10371863 | biostudies-literature

Plasmon-assisted radiolytic energy conversion in aqueous solutions.

Project description:The field of conventional energy conversion using radioisotopes has almost exclusively focused on solid-state materials. Herein, we demonstrate that liquids can be an excellent media for effective energy conversion from radioisotopes. We also show that free radicals in liquid, which are continuously generated by beta radiation, can be utilized for electrical energy generation. Under beta radiation, surface plasmon obtained by the metallic nanoporous structures on TiO₂ enhanced the radiolytic conversion via the efficient energy transfer between plasmons and free radicals. This work introduces a new route for the development of next-generation power sources.

| S-EPMC4052741 | biostudies-literature

Deciphering the Properties of Nanoconfined Aqueous Solutions by Vibrational Sum Frequency Generation Spectroscopy.

Project description:When confined between walls at nanometer distances, water exhibits surprisingly different properties with reference to bare interfacial water. Based on computer simulations, we demonstrate how vibrational sum frequency generation (VSFG) spectroscopy can be used-even with very mild symmetry breaking-to discriminate multilayer water in wide slit pores from both bilayer and monolayer water confined within molecularly narrow pores. Applying the technique, the VSFG lineshapes of monolayer, bilayer, and multilayer water are found to differ in characteristic ways, which is explained by their distinct density stratifications giving rise to different H-bonding patterns in the respective solvation layers.

| S-EPMC9923734 | biostudies-literature

Laser-Induced Shockwave Crystallization in Supersaturated Solutions and Conceivable Clustering in Undersaturated Aqueous Potassium Nitrate Solutions.

Project description:In this study, a newly developed setup based on laser-induced shockwave crystallization coupled with electric conductivity monitoring was employed to study the growth of crystals in supersaturated solutions and to investigate possible clustering in undersaturated solutions of potassium nitrate (KNO3). A comparison was drawn between crystals induced by laser irradiation, by shockwaves, and spontaneously in terms of crystals' mean size, shape, and size distribution. The size distribution of produced crystals by shockwaves was also characterized in terms of laser irradiation time. The results show that produced crystals by shockwaves propagation have the sharpest size distribution and the smallest mean dimensions compared to crystals grown spontaneously or by direct laser induction. Real-time monitoring of nucleation was also performed in supersaturated solutions, while decrease in conductivity was observed in undersaturated solutions as a function of laser irradiation time.

| S-EPMC9631718 | biostudies-literature

Ion pairing in molecular simulations of aqueous alkali halide solutions.

Project description:Using classical molecular dynamics simulations, we study ion-ion interactions in water. We study the potentials of mean force (PMF) for the full set of alkali halide ion pairs, and in each case, we test different parameter sets for modeling both the water and the ions. Altogether, we compared 300 different PMFs. We also calculate association equilibrium constants (KA) and compare them to two types of experiments. Of additional interest here was the proposition of Collins called the "law of matching water affinities", where the relative affinity of ions in solution depends on the matching of cation and anion sizes. From observations on the relative depths of the free energies of the contact ion pair (CIP) and the solvent-shared ion pair (SIP), along with related solvent structure analyses, we find a good correlation with this proposition: small-small and large-large should associate in water, and small-large should be more dissociated.

| S-EPMC2698044 | biostudies-literature

Role of atomic contacts in vibrational energy transfer in myoglobin.

Project description:Heme proteins are ideal systems to investigate vibrational energy flow at the atomic level. Upon photoexcitation, a large amount of excess vibrational energy is selectively deposited on heme due to extremely fast internal conversion. This excess energy is redistributed to the surrounding protein moiety and then to water. Vibrational energy flow in myoglobin (Mb) was examined using picosecond time-resolved anti-Stokes ultraviolet resonance Raman (UVRR) spectroscopy. We used the Trp residue directly contacting the heme group as a selective probe for vibrationally excited populations. Trp residues were placed at different position close to the heme by site-directed mutagenesis. This technique allows us to monitor the excess energy on residue-to-residue basis. Anti-Stokes UVRR measurements for Mb mutants suggest that the dominant channel for energy transfer in Mb is the pathway through atomic contacts between heme and nearby amino acid residues as well as that between the protein and solvent water. It is found that energy flow through proteins is analogous to collisional exchange processes in solutions.

| S-EPMC7242529 | biostudies-literature

Coherent exciton-vibrational dynamics and energy transfer in conjugated organics.

Project description:Coherence, signifying concurrent electron-vibrational dynamics in complex natural and man-made systems, is currently a subject of intense study. Understanding this phenomenon is important when designing carrier transport in optoelectronic materials. Here, excited state dynamics simulations reveal a ubiquitous pattern in the evolution of photoexcitations for a broad range of molecular systems. Symmetries of the wavefunctions define a specific form of the non-adiabatic coupling that drives quantum transitions between excited states, leading to a collective asymmetric vibrational excitation coupled to the electronic system. This promotes periodic oscillatory evolution of the wavefunctions, preserving specific phase and amplitude relations across the ensemble of trajectories. The simple model proposed here explains the appearance of coherent exciton-vibrational dynamics due to non-adiabatic transitions, which is universal across multiple molecular systems. The observed relationships between electronic wavefunctions and the resulting functionalities allows us to understand, and potentially manipulate, excited state dynamics and energy transfer in molecular materials.

| S-EPMC5998141 | biostudies-literature

Vibrational couplings and energy transfer pathways of water's bending mode.

Project description:Coupling between vibrational modes is essential for energy transfer and dissipation in condensed matter. For water, different O-H stretch modes are known to be very strongly coupled both within and between water molecules, leading to ultrafast dissipation and delocalization of vibrational energy. In contrast, the information on the vibrational coupling of the H-O-H bending mode of water is lacking, even though the bending mode is an essential intermediate for the energy relaxation pathway from the stretch mode to the heat bath. By combining static and femtosecond infrared, Raman, and hyper-Raman spectroscopies for isotopically diluted water with ab initio molecular dynamics simulations, we find the vibrational coupling of the bending mode differs significantly from the stretch mode: the intramode intermolecular coupling of the bending mode is very weak, in stark contrast to the stretch mode. Our results elucidate the vibrational energy transfer pathways of water. Specifically, the librational motion is essential for the vibrational energy relaxation and orientational dynamics of H-O-H bending mode.

| S-EPMC7688972 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data