Electronic structure ofparaaminophenoxyl radical in water
| Autor: | G. N. R. Tripathi |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Chemistry
Transition dipole moment Resonance Raman spectroscopy Ab initio General Physics and Astronomy Electronic structure Photochemistry symbols.namesake Vibronic coupling Ab initio quantum chemistry methods symbols Density functional theory Physics::Chemical Physics Physical and Theoretical Chemistry Raman spectroscopy |
| Zdroj: | The Journal of Chemical Physics. 118:1378-1391 |
| ISSN: | 1089-7690 0021-9606 |
| DOI: | 10.1063/1.1528899 |
| Popis: | The electronic structure of aqueous p-aminophenoxyl radical (H2NPhO•) has been examined by time-resolved resonance Raman spectroscopy and ab initio and density functional theories. The effects of hydrogen bonding and solvent reaction field on polarity of the radical have been visualized in terms of simple models. Calculations predict the dipole moment of the radical in its ground electronic state (2B1) to increase by 8(±2) D and the difference between the CN and CO bond lengths to decrease by ∼0.05 A from gas phase to aqueous solution. This profound hydration effect converts the structure and chemical properties of H2NPhO• from a substituted phenoxyl radical in the gas phase to a semiquinone-like radical in water. The observation of vibrational modes enhanced in Raman by a non-Franck–Condon vibronic coupling mechanism has led to the identification of two very weakly absorbing electronic states of 2A2 symmetry in the 340–390 nm region, which borrow transition moment from close by strongly allowed electroni... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|