Dissociative electron attachment and electron energy-loss spectra of phenyl azide

Abstract

Electron-induced chemistry-dissociative electron attachment (DEA)-was studied for phenyl azide. The major fragment corresponded to the loss of N 2 and formation of the phenylnitrene anion. This process has an onset already at zero kinetic energy of the incident electron and is interpreted as proceeding via the A π * electronic ground state of the phenyl azide anion. Other fragments, N − 3 and CN − , were observed at higher energies and interpreted as proceeding via low-lying shape resonances or higher lying core-excited resonances. The interpretation of the dissociative attachment spectra was supported by an investigation of the excited electronic states of neutral phenyl azide by electron energy-loss spectroscopy and DFT/MRCI calculations, and a study of shape and core-excited resonances of the phenyl azide anion by means of electron transmission spectroscopy and of cross sections for vibrational and electronic excitation by electron impact. Interesting parallels and differences are found by comparing DEA of phenyl and benzyl azides with the corresponding chloro compounds.

Low-energy electron elastic scattering cross sections for excited Au and Pt atoms

“…This has been exploited to synthesize the first ionic compound Cs 2 Pt containing Pt atoms in a negative oxidation state [24], namely (Cs 2+ )Pt 2À ; its stability is attributed partly to the strong polarization of the Pt 2À ions and the Cs 2+ shells. Furthermore, dissociative electron attachment has been investigated in phenyl azide, with the interpretation that the observed negative ion fragments at higher energies are generated through low-lying shape resonances or higher core-excited resonances [25]. Hence, the importance and the timeliness of this investigation.…”

“…The Wigner threshold law [29] is essential in high precision measurements of BEs of valence electrons using photodetachment threshold spectroscopy [30]. Shape resonances are useful for interpreting electron-induced chemical processes resulting in negative ion production [3,25]. The Ramsauer-Townsend minima, manifesting the polarization of the atomic core by the scattered electron [31], are important among other things in the understanding of sympathetic cooling and the production of cold molecules from natural fermions [32].…”

Site of Azido Substitution in the Sugar Moiety of Azidopyrimidine Nucleosides Influences the Reactivity of Aminyl Radicals Formed by Dissociative Electron Attachment

“…Following our analyses of the green spectrum in Figure 1A, spectra presented in Figure 2 We note here that these results, along with our previous results on radiation-produced prehydrated electron-mediated formation of RNH• and their reactions in 5-azidopyrimidines, 7 AZT derivatives, 8 and azidopentoses, 9 reported predominant formation of phenylnitrene anion radical due to gas-phase lowenergy electron (LEE, 0 to 1 eV) attachment to phenylazide. 8,52,53 Light-induced reduction of aromatic azides to amines in the presence of CdS and CdSe nanoparticles 8,54 showed the facile and site-specific formation of RNH• from a localized RN 3 • − (Scheme 3). In addition, pulse radiolysis carried out in aqueous solution of 3′-AZT at ambient temperature reports that the solvated (aqueous) electron reacts with 3′-AZT with a diffusion-controlled rate (k = 1.9 × 10 10 M −1 s −1 ), 55 thereby supporting the reaction mechanism and its facile nature represented in Scheme 3.…”

Photoion-pair dissociation dynamics of polyatomic molecules with synchrotron radiation

“…. 26,27 A simple and reasonable method has been successfully used by Tuckett's group 12 and ours. Namely, the ion-pair dissociation overwhelming the DEA process can be confirmed by the observation of the linear increase in the signal of C À with the concentration or pressure of ABC.…”