Electrons in Liquid Ammonia

Thompson, J.C.; Barradas, R.G.

doi:10.1149/1.2133504

Cited by 136 publications

(193 citation statements)

References 0 publications

Supporting

Mentioning

181

Contrasting

Unclassified

Order By: Relevance

“…give estimates for average 17 O and 1 H hfcc constants that are comparable to the averages obtained using more diffuse basis sets (Table 4S). Isotropic hfcc's for protons are small ( a H < 1 G): either slightly negative or slightly positive (Table 3S).…”

supporting

confidence: 62%

“…suggesting that EPR results of Schlick et al 30 for 17 O substituted glasses (used to justify the one-electron models) were compromised, as was also suggested by subsequent studies by the same authors (section 2). 49 While the one-electron point-dipole octahedral ("Kevan's") model 24 While the magnetic parameters for different trapping sites show considerable variation, the mean values are similar to the ones obtained in simple cluster models provided that the mean cavity size is the same.…”

Section: Discussionmentioning

confidence: 75%

“…In Part 2, 7 we suggest that the narrow resonance line of the electron in oxygen-17 substituted sample was from isotopic configurations in which 17 O nuclei are in the second rather than the first solvation shell. The latter yield extremely broad EPR lines that are difficult to observe using EPR, especially in the presence of many other lines.…”

mentioning

confidence: 93%

“…Yet the approach also allows to estimate the magnetic parameters for the 1 H and 17 believed to be trapped by a Bjerrum proton disorder defect in ice, 34b,35 whereas electron-2 is believed to occupy a relatively undistorted hexagonal cavity. 36 Neither of these attributions have been proved.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The Structure of the Hydrated Electron. Part 1. Magnetic Resonance of Internally Trapping Water Anions: A Density Functional Theory Study

Shkrob

2007

J. Phys. Chem. A

View full text Add to dashboard Cite

Density functional theory (DFT) is used to rationalize magnetic parameters of hydrated electron trapped in alkaline glasses as observed using Electron Paramagnetic Resonance (EPR) and Electron Spin Echo Envelope Modulation (ESEEM) spectroscopies. To this end, model water cluster anions (n=4-8 and n=20,24) that localize the electron internally are examined. It is shown that EPR parameters of such water anions (such as hyperfine coupling tensors of H/D nuclei in the water molecules) are defined mainly by the cavity size and the coordination number of the electron; the water molecules in the second solvation shell play a relatively minor role. An idealized model of hydrated electron (that is usually attributed to L. Kevan) in which six hydroxyl groups arranged in an octahedral pattern point towards the common center is shown to provide the closest match to the experimental parameters, such as isotropic and anisotropic hyperfine coupling constants for the protons (estimated from ESEEM), the second moment of the EPR spectra, and the radius of gyration. The salient feature of these DFT models is the significant transfer (10-20%) of spin density into the frontal O 2p orbitals 2.of water molecules. Spin bond polarization involving these oxygen orbitals accounts for small, negative hyperfine coupling constants for protons in hydroxyl groups that form the electron-trapping cavity. In Part 2, these results are generalized for more realistic geometries of core anions obtained using a dynamic one-electron mixed qunatum/classical molecular dynamics model.

show abstract

supporting

confidence: 62%

Section: Discussionmentioning

confidence: 75%

mentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Structure of the Hydrated Electron. Part 1. Magnetic Resonance of Internally Trapping Water Anions: A Density Functional Theory Study

Shkrob

2007

J. Phys. Chem. A

View full text Add to dashboard Cite

show abstract

“…8 In fact, there is indirect experimental evidence for the formation of bound pairs of electrons in solutions of metals dissolved in liquid ammonia; the metal/ammonia solutions show a decrease in magnetic susceptibility at high concentrations of excess electrons, suggesting that the electrons' spins become paired. 9 Mixed quantum/classical density functional calculations also have suggested that bound pairs of electrons form at high electron densities in liquid ammonia. 10 In water, simulations have shown 11 that hydrated dielectrons occupy a larger, less spherical cavity than (single) hydrated electrons.…”

Section: Introductionmentioning

confidence: 99%

Full Configuration Interaction Computer Simulation Study of the Thermodynamic and Kinetic Stability of Hydrated Dielectrons

Larsen

Schwartz

2005

J. Phys. Chem. B

View full text Add to dashboard Cite

The hydrated electron is a unique solvent-supported state comprised of an excess electron that is confined to a cavity by the surrounding water. Theoretical studies have suggested that two-electron solvent-supported states also can be formed; in particular, simulations indicate that two excess electrons could pair up and occupy a single cavity, forming a so-called hydrated dielectron. Although hydrated dielectrons have not been observed directly by experiment, their existence has been posited to explain the lack of an ionic strength effect in hydrated electron bimolecular annihilation [Schmidt, K. H.; Bartels, D. M. Chem. Phys. 1995, 190, 145]. To determine whether dielectrons may be created in the laboratory, we use thermodynamic integration (TI), combined with mixed quantum/classical molecular dynamics simulation, to examine the thermodynamic stability of hydrated electrons and dielectrons. For the dielectron calculations, we solve the two-electron quantum problem using full configuration interaction. Our results suggest that hydrated dielectrons are thermodynamically unstable relative to separated (single) hydrated electrons, although we also show that increasing the pressure could drive the equilibrium toward the formation of dielectrons. Because the simulations suggest that hydrated dielectrons are kinetically stable, we also examine a scenario for creating metstable, nonequilibrium populations of dielectrons, which involves the capture of a newly injected electron by a preexisting, equilibrated hydrated electron. These calculations, which allow for the full nonadiabatic relaxation of the injected electron, show that hydrated electrons may indeed act as trapping sites for unequilibrated electrons, so that capture may be a viable mechanism for creating dielectrons. We suggest possible experimental procedures to create such nonequilibrium hydrated dielectrons using either pulse radiolysis or ultrafast spectroscopic techniques.

show abstract

Ab Initio Studies on the Mechanism of the Size-Dependent Hydrogen-Loss Reaction in Mg+(H2O)n

Siu¹,

Liu²

2002

Chem. Eur. J.

View full text Add to dashboard Cite

show abstract

Electrons in Liquid Ammonia

Abstract: not Available.

Cited by 136 publications

References 0 publications

The Structure of the Hydrated Electron. Part 1. Magnetic Resonance of Internally Trapping Water Anions: A Density Functional Theory Study

The Structure of the Hydrated Electron. Part 1. Magnetic Resonance of Internally Trapping Water Anions: A Density Functional Theory Study

Full Configuration Interaction Computer Simulation Study of the Thermodynamic and Kinetic Stability of Hydrated Dielectrons

Ab Initio Studies on the Mechanism of the Size-Dependent Hydrogen-Loss Reaction in Mg+(H2O)n

Contact Info

Product

Resources

About