| Autor: |
C Cabral BJ; BioISI-Biosystems and Integrative Sciences Institute and Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal. |
| Jazyk: |
angličtina |
| Zdroj: |
The Journal of chemical physics [J Chem Phys] 2017 Jun 21; Vol. 146 (23), pp. 234502. |
| DOI: |
10.1063/1.4985667 |
| Abstrakt: |
Results for the magnetic properties and electron binding energies of H 2 O 2 in liquid water are presented. The adopted methodology relies on the combination of Born-Oppenheimer molecular dynamics and electronic structure calculations. The Keal-Tozer functional was applied for predicting magnetic shieldings and H 2 O 2 intramolecular spin-spin coupling constants. Electron binding energies were calculated with electron propagator theory. In water, H 2 O 2 is a better proton donor than proton acceptor, and the present results indicate that this feature is important for understanding magnetic properties in solution. In comparison with the gas-phase, H 2 O 2 atoms are deshielded in water. For oxygen atoms, the deshielding is mainly determined by structural/conformational changes. Hydrogen-bond interactions explain the deshielding of protons in water. The predicted chemical shift for the H 2 O 2 protons in water (δ∼11.8 ppm) is in good agreement with experimental information (δ=11.2 ppm). The two lowest electron binding energies of H 2 O 2 in water (10.7±0.5 and 11.2±0.5 eV) are in reasonable agreement with experiment. In keeping with data from photoelectron spectroscopy, an ∼1.6 eV red-shift of the two first ionisation energies relative to the gas-phase is observed in water. The strong dependence of magnetic properties on changes of the electronic density in the nuclei environment is illustrated by a correlation between the σ( 17 O) magnetic shielding constant and the energy gap between the [2a] lowest valence and [1a] core orbitals of H 2 O 2 . |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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