Artículos de revistas
Precursor Anion States In Dissociative Electron Attachment To Chlorophenol Isomers
Registro en:
Journal Of Chemical Physics. American Institute Of Physics Inc., v. 145, p. , 2016.
00219606
10.1063/1.4959229
2-s2.0-84979738984
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) We report a theoretical study on low-energy (<10 eV) elastic electron scattering from chlorophenol isomers, namely, para-chlorophenol (pCP), meta-chlorophenol (mCP), and ortho-chlorophenol (oCP). The calculations were performed with the Schwinger multichannel method with pseudopotentials, and analysis of the computed integral cross sections and virtual orbitals revealed one σ∗ CCl one σ∗ OH and three π∗ shape resonances. We show that electron capture into the two lower lying π∗ orbitals initiates dissociative processes that lead to the elimination of the chloride ion, accounting for the two overlapping peaks where this fragment was observed. Despite the relatively small differences on the energetics of the π∗ resonances, a major isomeric effect was found on their corresponding autodetachment lifetimes, which accounts for the observed increasing cross sections in the progression pCP < mCP < oCP. In particular, dissociation from the π∗ 1 anion of pCP is largely suppressed because of the unfavorable mixing with the σ∗ CCl state. We found the intramolecular hydrogen bond present in oCP to have the opposite effects of stabilizing the σ∗ CCl resonance and destabilizing the σ∗ OH resonance. We also suggest that the hydrogen abstraction observed in chlorophenols and phenol actually takes place by a mechanism in which the incoming electron is directly attached to the dissociative σ∗ OH orbital. © 2016 Author(s). 145
FAPESP, São Paulo Research Foundation Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)