Dynamics, magnetic properties, and electron binding energies of H2O2 in water

• Published in: The Journal of chemical physics 2017-06, Vol.146 (23), p.234502-234502
• Main Author: C Cabral, Benedito J
• Format: Article
• Language: English
• Subjects: Binding energy; Chemical equilibrium; Coupling (molecular); Dependence; Electron spin; Electronic structure; Electrons; Energy gap; Hydrogen peroxide; Ionization; Magnetic properties; Magnetic shielding; Mathematical analysis; Molecular dynamics; Molecular structure; Nuclei (nuclear physics); Organic chemistry; Oxygen atoms; Spin-spin coupling; Water
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.4985667

Results for the magnetic properties and electron binding energies of H2O2 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 H2O2 intramolecular spin-spin coupling constants. Electron binding energies were calculated with electron propagator theory. In water, H2O2 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, H2O2 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 H2O2 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 H2O2 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(17O) magnetic shielding constant and the energy gap between the [2a] lowest valence and [1a] core orbitals of H2O2.