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Photoelectron Spectroscopy Study of Quinonimides.

Ekram HossainShihu M DengSamer GozemAnna I KrylovXue-Bin WangPaul G Wenthold
Published in: Journal of the American Chemical Society (2017)
Structures and energetics of o-, m-, and p-quinonimide anions (OC6H4N-) and quinoniminyl radicals have been investigated by using negative ion photoelectron spectroscopy. Modeling of the photoelectron spectrum of the ortho isomer shows that the ground state of the anion is a triplet, while the quinoniminyl radical has a doublet ground state with a doublet-quartet splitting of 35.5 kcal/mol. The para radical has doublet ground state, but a band for a quartet state is missing from the photoelectron spectrum indicating that the anion has a singlet ground state, in contrast to previously reported calculations. The theoretical modeling is revisited here, and it is shown that accurate predictions for the electronic structure of the para-quinonimide anion require both an accurate account of electron correlation and a sufficiently diffuse basis set. Electron affinities of o- and p-quinoniminyl radicals are measured to be 1.715 ± 0.010 and 1.675 ± 0.010 eV, respectively. The photoelectron spectrum of the m-quinonimide anion shows that the ion undergoes several different rearrangements, including a rearrangement to the energetically favorable para isomer. Such rearrangements preclude a meaningful analysis of the experimental spectrum.
Keyphrases
  • ionic liquid
  • high resolution
  • molecular dynamics
  • molecular dynamics simulations
  • quantum dots
  • energy transfer
  • contrast enhanced
  • solid state
  • monte carlo