| Autor: |
Jie Yang, Xiao-Peng Xing, Xue-Bin Wang, Lai-Sheng Wang, Sergeeva, Alina P., Boldyrev, Alexander I. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 3/7/2008, Vol. 128 Issue 9, p091102, 4p, 2 Diagrams, 1 Chart, 1 Graph |
| Abstrakt: |
We report the observation of negative electron binding energies (BEs) in a triply charged anion, 1-hydroxy-3,6,8-pyrene-trisulfonate (HPTS3-). Low-temperature photoelectron spectra were obtained for HPTS3- at several photon energies, revealing three detachment features below 0 electron BE. The HPTS3- trianion was measured to possess a negative BE of -0.66 eV. Despite the relatively high excess energy stored in HPTS3-, it was observed to be a long-lived anion due to its high repulsive Coulomb barrier (RCB) (∼3.3 eV), which prevents spontaneous electron emission. Theoretical calculations were carried out, which confirmed the negative electron BEs observed. The calculations further showed that the highest occupied molecular orbital in HPTS3- is an antibonding π orbital on the pyrene rings, followed by lone pair electrons in the peripheral –SO3- groups. Negative electron BE is a unique feature of multiply charged anions due to the presence of the RCB. Such metastable species may be good models to study electron-electron and vibronic interactions in complex molecules. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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