Water in a Crowd

Physiology ◽  
2011 ◽  
Vol 26 (6) ◽  
pp. 381-392 ◽  
Author(s):  
Michael D. Fayer
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Proton Transport ◽  
Organic Molecules ◽  
Ionic Species ◽  
Water Dynamics ◽  
Bulk Liquid ◽  
Hydrogen Bond Dynamics ◽  
Shed Light ◽  
Water Hydrogen

In many situations, form biology to geology, water occurs not as the pure bulk liquid but rather in nanoscopic environments, in contact with interfaces, interacting with ionic species, and interacting with large organic molecules. In such situations, water does not behave in the same manner as it does in the pure bulk liquid. Water dynamics are fundamental to many processes such as protein folding and proton transport. Such processes depend on the dynamics of water's hydrogen bonding network. Here, the results of ultrafast infrared experiments are described that shed light on the influences of nanoconfinement, interfaces, ions, and organic molecules on water hydrogen bond dynamics.

Water dynamics at electrified graphene interfaces: a jump model perspective

2020 ◽  
Vol 22 (19) ◽  
pp. 10581-10591 ◽  
Author(s):  
Yiwei Zhang ◽  
Guillaume Stirnemann ◽  
James T. Hynes ◽  
Damien Laage
Keyword(s):  
Hydrogen Bond ◽  
Electrode Potential ◽  
Water Dynamics ◽  
Asymmetric Behavior ◽  
Jump Model ◽  
Reorientation Dynamics ◽  
Potential Sign ◽  
Water Hydrogen

Changes in water reorientation dynamics at electrified graphene interfaces arise from the interfaces’ impact on water hydrogen-bond exchanges; the asymmetric behavior with electrode potential sign is quantitatively described by an extended jump model.

Water Hydrogen Bond Dynamics in Aqueous Solutions of Amphiphiles

2010 ◽  
Vol 114 (8) ◽  
pp. 3052-3059 ◽  
Author(s):  
Guillaume Stirnemann ◽  
James T. Hynes ◽  
Damien Laage
Keyword(s):  
Hydrogen Bond ◽  
Aqueous Solutions ◽  
Hydrogen Bond Dynamics ◽  
Water Hydrogen

scholarly journals Water in Hydration Shell of an Azide Ion: Structure and Dynamics of Solute-water Hydrogen Bonds and Vibrational Spectral Diffusion from First Principles Simulations At Supercritical Condition

2019 ◽  
Author(s):  
Anwesa Karmakar
Keyword(s):  
Hydrogen Bond ◽  
Hydration Shell ◽  
Solvation Shell ◽  
Spectral Diffusion ◽  
Supercritical Condition ◽  
Time Dependent ◽  
Dynamics Simulation ◽  
Azide Ion ◽  
Hydrogen Bond Dynamics ◽  
Water Hydrogen

<p>A series of ab initio MD simulations has been carried out for aqueous azide (N<sub>3</sub><sup>-</sup>) ion solutions at three different densities and at supercritical condition (673 K) using Car-Parrinello molecular dynamics simulation. The time dependent trajectories at three different densities have been used to analyze the hydrogen bond dynamics, residence dynamics, dangling OD bond dynamics and spectral diffusion and underlying connections between them. The time dependent frequency of both the OD and NN stretching mode has been calculated using the time series analysis of the wavelet method. The population correlation function approach has been used to compute the hydrogen bond dynamics, dangling OD bond and residence dynamics of the Sc-water both inside and outside the solvation shell of the ion. The faster hydrogen bond dynamics has been observed in the vicinity of the azide ion, however the calculated OD stretching frequency is found to show red shift in the vicinity of the azide ion indicative to the formation of stronger ion-water hydrogen bond even at the supercritical condition. The overall hydrogen bond dynamics at the supercritical condition was faster with respect to the aqueous azide ion solutions at the ambient condition.</p>

Specific Ion Effects on Hydrogen-Bond Rearrangements in the Halide–Dihydrate Complexes

2019 ◽  
Author(s):  
Pushp Bajaj ◽  
Debbie Zhuang ◽  
Francesco Paesani
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Quantum Molecular Dynamics ◽  
Ion Hydration ◽  
Systematic Analysis ◽  
Bonding Structure ◽  
Specific Ion Effects ◽  
Hydration Shells ◽  
Ion Effects ◽  
Water Hydrogen

<div> <div> <div> <p>Small aqueous ionic clusters represent ideal systems to investigate the microscopic hydrogen-bonding structure and dynamics in ion hydration shells. In this context, halide-dihydrate complexes are the smallest systems where the interplay between halide–water and water–water interactions can be studied simultaneously. Here, quantum molecular dynamics simulations unravel specific ion effects on the temperature-dependent structural transition in X<sup>-</sup>(H<sub>2</sub>O)<sub>2</sub> complexes (X = Cl, Br and I) which is induced by the breaking of the water–water hydrogen bond. A systematic analysis of the hydrogen-bonding rearrangements at low temperature provides fundamental insights into the competition between halide–water and water–water interactions depending on the properties of the halide ion. While the halide–water hydrogen-bond strength decreases going from Cl<sup>-</sup>(H<sub>2</sub>O)<sub>2</sub> to I<sup>-</sup>(H<sub>2</sub>O)<sub>2</sub>, the opposite trend in observed in the strength of the water–water hydrogen-bond, suggesting that non-trivial many-body effects may also be at play in the hydration shells of halide ions in solution, especially in frustrated systems (e.g., interfaces) where the water molecules can have dangling OH bonds.</p> </div> </div> </div>

scholarly journals Probing Interfacial Effects on Ionization Energies: The Surprising Banality of Anion-Water Hydrogen Bonding at the Air/Water Interface

2021 ◽  
Author(s):  
Suranjan Paul ◽  
John Herbert
Keyword(s):  
Hydrogen Bonding ◽  
Photoelectron Spectroscopy ◽  
Solvation Shell ◽  
Bulk Liquid ◽  
Water Interface ◽  
Simulation Data ◽  
Ionization Energies ◽  
Air Water Interface ◽  
Dynamics Simulations ◽  
Water Hydrogen

Liquid microjet photoelectron spectroscopy is an increasingly common technique to measure vertical ionization energies (VIEs) of aqueous solutes, although the interpretation of these experiments is subject to questions regarding sensitivity to bulk versus interfacial solvation environments. Here, we compute aqueous-phase VIEs for a set of inorganic anions, some of which partition preferentially at the air/water interface, using a combination of molecular dynamics simulations and electronic structure calculations. The results are in excellent agreement with experiment, regardless of whether the simulation data are restricted to ions at the air/water interface or to those in bulk liquid water. Although the computed VIEs are sensitive to ion-water hydrogen bonding, we find that the short-range solvation structure is sufficiently similar in the bulk and interfacial environments that it proves impossible to discriminate between the two on the basis of the VIE, a conclusion that has important implications for the interpretation of liquid-phase photoelectron spectroscopy. More generally, analysis of the simulation data suggests that partitioning of soft anions at the air/water interface is largely a second (or third) solvation shell effect, arising from disruption of water-water hydrogen bonds and not from significant changes in first-shell anion-water hydrogen bonding. <br>

scholarly journals Co-crystallization of a neutral molecule and its zwitterionic tautomer: structure and Hirshfeld surface analysis of 5-methyl-4-(5-methyl-1H-pyrazol-3-yl)-2-phenyl-2,3-dihydro-1H-pyrazol-3-one 5-methyl-4-(5-methyl-1H-pyrazol-2-ium-3-yl)-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-1-ide monohydrate

2019 ◽  
Vol 75 (5) ◽  
pp. 565-570
Author(s):  
Abdullah M. Asiri ◽  
Khalid A. H. Alzahrani ◽  
Hassan M. Faidallah ◽  
Khalid A. Alamry ◽  
Mukesh M. Jotani ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Organic Molecules ◽  
Three Dimensional ◽  
Phenyl Group ◽  
Hirshfeld Surface ◽  
Neutral Molecule ◽  
Dihedral Angles ◽  
Central Ring ◽  
Hirshfeld Surfaces ◽  
Water Hydrogen

The title compound, 2C14H14N4O·H2O, comprises a neutral molecule containing a central pyrazol-3-one ring flanked by an N-bound phenyl group and a C-bound 5-methyl-1H-pyrazol-3-yl group (at positions adjacent to the carbonyl substituent), its zwitterionic tautomer, whereby the N-bound proton of the central ring is now resident on the pendant ring, and a water molecule of crystallization. Besides systematic variations in geometric parameters, the two independent organic molecules have broadly similar conformations, as seen in the dihedral angle between the five-membered rings [9.72 (9)° for the neutral molecule and 3.32 (9)° for the zwitterionic tautomer] and in the dihedral angles between the central and pendant five-membered rings [28.19 (8) and 20.96 (8)° (neutral molecule); 11.33 (9) and 11.81 (9)°]. In the crystal, pyrazolyl-N—H...O(carbonyl) and pyrazolium-N—H...N(pyrazolyl) hydrogen bonds between the independent organic molecules give rise to non-symmetric nine-membered {...HNNH...NC3O} and {...HNN...HNC3O} synthons, which differ in the positions of the N-bound H atoms. These aggregates are connected into a supramolecular layer in the bc plane by water-O—H...N(pyrazolide), water-O—H...O(carbonyl) and pyrazolyl-N—H...O(water) hydrogen bonding. The layers are linked into a three-dimensional architecture by methyl-C—H...π(phenyl) interactions. The different interactions, in particular the weaker contacts, formed by the organic molecules are clearly evident in the calculated Hirshfeld surfaces, and the calculated electrostatic potentials differentiate the tautomers.

scholarly journals Analysis of Water and Hydrogen Bond Dynamics at the Surface of an Antifreeze Protein

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Yao Xu ◽  
Ramachandran Gnanasekaran ◽  
David M. Leitner
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Protein Function ◽  
Choristoneura Fumiferana ◽  
Power Spectra ◽  
Antifreeze Protein ◽  
Water Dynamics ◽  
Water Molecules ◽  
Wild Type ◽  
Hydrogen Bond Dynamics

We examine dynamics of water molecules and hydrogen bonds at the water-protein interface of the wild-type antifreeze protein from spruce budworm Choristoneura fumiferana and a mutant that is not antifreeze active by all-atom molecular dynamics simulations. Water dynamics in the hydration layer around the protein is analyzed by calculation of velocity autocorrelation functions and their power spectra, and hydrogen bond time correlation functions are calculated for hydrogen bonds between water molecules and the protein. Both water and hydrogen bond dynamics from subpicosecond to hundred picosecond time scales are sensitive to location on the protein surface and appear correlated with protein function. In particular, hydrogen bond lifetimes are longest for water molecules hydrogen bonded to the ice-binding plane of the wild type, whereas hydrogen bond lifetimes between water and protein atoms on all three planes are similar for the mutant.

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