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Title: Electron attachment to the phthalide molecule

Phthalide, the simplest chain of conductive polymer thin film, was investigated by means of Electron Transmission Spectroscopy, Negative Ion Mass Spectrometry, and density functional theory quantum chemistry. It has been found that formation of gas-phase long-lived molecular anions of phthalide around 0.7 eV takes place through cleavage of a C–O bond of the pentacyclic ring of the parent molecular anion to give a vibrationally excited (electronically more stable) open-ring molecular anion. The energy of the transition state for ring opening of the parent negative ion is calculated to be 0.65 eV above the neutral ground state of the molecule. The energy (2.64 eV) evaluated for the corresponding transition state in the neutral molecule is much higher, so that the process of electron detachment from the anion must lead to a neutral molecule with its initial pentacyclic structure. The average lifetime of the molecular negative ions formed at an electron energy of 0.75 eV and 80 °C is measured to be about 100 μs. The known switching effect of thin phthalide films could stem from the presence of a similar open/closed transition state also in the polymer.
Authors:
 [1] ;  [2] ;  [1] ;  [2] ; ;  [1] ;  [3] ;  [4] ;  [5] ;  [6]
  1. Institute of Molecule and Crystal Physics, Ufa Research Centre, Russian Academy of Sciences, Prospect Oktyabrya 151, 450075 Ufa (Russian Federation)
  2. (Russian Federation)
  3. Bashkir State Pedagogical University, Oktyabrskoy Revolutsii St., 3a, 450000 Ufa (Russian Federation)
  4. Institute of Organic Chemistry, Ufa Research Centre, Russian Academy of Sciences, Prospect Oktyabrya 59, 450075 Ufa (Russian Federation)
  5. Dipartimento di Chimica “G. Ciamician,” Universitá di Bologna, Via Selmi 2, 40126 Bologna (Italy)
  6. (CIRSA), Universitá di Bologna, Via S. Alberto 163, 48123 Ravenna (Italy)
Publication Date:
OSTI Identifier:
22415744
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ANIONS; CHEMISTRY; DENSITY FUNCTIONAL METHOD; ELECTRON ATTACHMENT; ELECTRON DETACHMENT; ELECTRONS; EV RANGE; GROUND STATES; LIFETIME; MASS SPECTROSCOPY; MOLECULES; POLYMERS; THIN FILMS