Université de Fribourg

Partial cross sections for dissociative electron attachment to tetrahydrofuran reveal a dynamics-driven rich fragmentation pattern

Janečková, Radmila ; May, Olivier ; Milosavljević, A.R. ; Fedor, Juraj

In: International Journal of Mass Spectrometry, 2014, vol. 365–366, p. 163–168

We report partial absolute cross sections for dissociative electron attachment (DEA) to tetrahydrofuran C₄H₈O. The high sensitivity of the present setup, quantitative DEA spectrometer with time-of-flight analyzer, led to identification of a number of previously unreported fragments (CH₂⁻, OH⁻, CHO⁻, C₄H₅O⁻, C₃H₃⁻) thus revealing complex dissociation dynamics of the...

Université de Fribourg

Experimental evidence on the mechanism of dissociative electron attachment to formic acid

Janečková, Radmila ; Kubala, Dušan ; May, Olivier ; Fedor, Juraj ; Allan, Michael

In: Physical Review Letters, 2013, vol. 111, no. 21, p. 213201

Two mechanisms for dissociative electron attachment in HCOOH, the formation of HCOO−+H, were proposed in the literature: (i) via a direct electron attachment into a σ∗ resonance, augmented by dipole binding of the incident electron [G. A. Gallup et al., Phys. Rev. A 79, 042701 (2009)], and (ii) with the 1.8 eV π∗ resonance as a doorway state, linked to the products by...

Université de Fribourg

Dissociative electron attachment to methylacetylene and dimethylacetylene: Symmetry versus proximity

Janečková, Radmila ; May, Olivier ; Fedor, Juraj

In: Physical Review A - Atomic, Molecular, and Optical Physics, 2012, vol. 86, no. 05, p. 052702

We have measured absolute dissociative electron attachment (DEA) cross sections in methylacetylene (propyne, C₃H₄) and dimethylacetylene (but-2-yne, C₄H₆). The main feature in the low-energy DEA spectrum is a π* shape resonance giving rise to fragments at 3.4 eV in C₃H₄ and 4.0 eV in C₄H₆. The process C₃H₄+e→ C₃H₃ −+H proceeds via abstraction...

Université de Fribourg

Absolute cross sections for electron collisions with diacetylene: elastic scattering, vibrational excitation and dissociative attachment

Allan, Michael ; May, Olivier ; Fedor, Juraj ; Ibǎnescu, Bogdan C ; Andrić, Lidija ; Winstead, Carl ; McKoy, Vincent

In: Journal of Physics: Conference Series, 2012, vol. 388, no. 5, p. 052082

We present absolute experimental cross sections for elastic scattering, vibrational excitation by electron impact and for dissociative electron attachment to 1,3-butadiyne, as well as calculations of the elastic cross sections.

Université de Fribourg

Dissociative electron attachment to Pt(PF₃)₄—a precursor for Focused Electron Beam Induced Processing (FEBIP)

May, Olivier ; Kubala, Dušan ; Allan, Michael

In: Physical Chemistry Chemical Physics, 2012, no. 9, p. 2979-2982

Experimental absolute cross sections for dissociative electron attachment (DEA) to Pt(PF₃)₄ are presented. Fragment anions resulting from the loss of one, two, three and four PF₃ ligands as well as the Pt(PF₃)F⁻ and the F⁻ ions were observed. The parent anion Pt(PF₃)⁻₄ is too short-lived to be detected. The dominant process is loss of one ligand, with a very large cross section...