title: Electron attachment to some naphthoquinone derivatives: long-lived molecular anion formation.
abstract: BACKGROUND
  Electron Affinity (EA) is one of the fundamental properties of a molecule. EA values can be measured with various experimental methods, although their availability is still relatively limited. We make an attempt to use Dissociative Electron Attachment Spectroscopy (DEAS) data for evaluation of the EAs of twelve naphthoquinone (NQ) derivatives.
  
  
  METHODS
  Naphthoquinone (NQ) and eleven of its hydroxyl derivatives were investigated by means of DEAS. A combined investigation of NQ and juglone by means of the Electron Transmission Spectroscopy (ETS) and DEAS techniques, with the support of density functional theory (DFT) calculations, allowed us to elucidate the empty-level structures of NQ and its hydroxyl derivatives.
  
  
  RESULTS
  All molecules under investigation form extremely long-lived molecular anions associated with three resonant states (except for NQ, where only two long-lived resonances were observed). The hydroxyl substituents of NQ cause an increase in EA and number of internal degrees of freedom (N), and, as a result, an increase in the mean electron autodetachment lifetimes of the molecular negative ions (NIs). Evaluation of the EAs from the measured lifetimes of the molecular NIs through a simple Arrhenius approximation gives results in reasonable agreement with those obtained with DFT calculations.
  
  
  CONCLUSIONS
  NI lifetime measurements by means of a modified DEAS instrumentation can provide quantitative data of EA. A simple Arrhenius approximation seems to be adequate to describe the process of electron detachment from molecular anions.
authors.affiliation: Institute of Molecule and Crystal Physics, Ufa Research Centre, Russian Academy of Sciences, Prospect Oktyabrya 151, 450075, Ufa, Russia; Bashkir State Pedagogical University, Oktyabrskoy Revolutsii st. 3a, 450000, Ufa, Russia.
authors.forename: N L
authors.initials: NL
authors.lastname: Asfandiarov
authors.forename: S A
authors.initials: SA
authors.lastname: Pshenichnyuk
authors.forename: A S
authors.initials: AS
authors.lastname: Vorob'ev
authors.forename: E P
authors.initials: EP
authors.lastname: Nafikova
authors.forename: Y N
authors.initials: YN
authors.lastname: Elkin
authors.forename: D N
authors.initials: DN
authors.lastname: Pelageev
authors.forename: E A
authors.initials: EA
authors.lastname: Koltsova
authors.forename: A
authors.initials: A
authors.lastname: Modelli
mesh_terms: D000838:Anions / Q000737:chemistry*; D004583:Electrons; D013058:Mass Spectrometry; D009285:Naphthoquinones / Q000737:chemistry*
chemical_list: D000838:Anions; D009285:Naphthoquinones