Details

Autor(en) / Beteiligte

• Asher, James R.
• Doltsinis, Nikos L.
• Kaupp, Martin

Titel

Extended Car-Parrinello molecular dynamics and electronic g-tensors study of benzosemiquinone radical anion

Ist Teil von

• Magnetic resonance in chemistry, 2005-11, Vol.43 (S1), p.S237-S247

Ort / Verlag

Chichester, UK: John Wiley & Sons, Ltd

Erscheinungsjahr

2005

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Car‐Parrinello molecular dynamics simulations of benzoquinone and benzosemiquinone radical anion in both aqueous solution and the gas phase have been carried out at ambient conditions. Hydrogen bonding is considerably more extensive to the anionic than to the neutral aqueous system. In addition to the conventional hydrogen bonding to the carbonyl oxygen atoms, T‐stacked hydrogen bonding to the π‐system is statistically and energetically significant for the semiquinone anion but not for the neutral quinone. EPR g‐tensors have been calculated at DFT level for snapshots taken at regular intervals from the gas‐phase and solution semiquinone anion trajectories. Different criteria for extraction of semiquinone/water clusters from the solution trajectory give insight into the effects of different interactions on the g‐tensor, as does correlation of the g‐tensor with statistically significant hydrogen‐bond configurations identified along the trajectories. Comparison of gas‐phase and solution results indicates opposite directions of direct electronic and indirect structural influences of hydrogen bonding on g‐tensors. Short‐time oscillations in gx along the trajectory are due mainly to CO bond vibrations. Copyright © 2005 John Wiley & Sons, Ltd.