Dissociative electron attachment, electron transmission, and electron energy-loss study of the temporary negative ion of acetylene

Journal Article · Thu Oct 15 00:00:00 EDT 1987 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.452864· OSTI ID:6118953

Dressler, R; Allan, M

The three title electron-impact techniques are used to study the ground and excited states of acetylene negative ion and their decay processes. The ..pi..* resonance at 2.6 eV predissociates into C/sub 2/H/sup -/ and H. Four narrow resonances are observed in the transmission spectrum in the 7.5--9.5 eV region and assigned to Feshbach and core-excited shape resonances with double occupation of Rydberg orbitals and ground state positive ion core. These four resonances decay into low-lying Rydberg states of neutral acetylene, the first two undergo quasiresonant autodetachment ejecting low energy (<0.7 eV) electrons, and the lowest also dissociates to yield C/sup -//sub 2/. One additional resonance is observed in the C/sup -//sub 2/ yield, which is not observable in other decay channels. The shapes of the dissociative attachment bands differ qualitatively from the band shapes of the parent and grandparent states, indicating either a strong v dependence of the dissociation rate or the admixture of sigma* orbitals in some of the dissociating anion states.

• Research Organization: Institut de Chimie Physique de l'Universite de Fribourg, 1700 Fribourg, Switzerland
• OSTI ID: 6118953
• Journal Information: J. Chem. Phys.; (United States), Vol. 87:8
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ACETYLENE
ELECTRON-ION COLLISIONS
DISSOCIATION
ELECTRON ATTACHMENT
ANIONS
RESONANCE
RYDBERG STATES
ALKYNES
CHARGED PARTICLES
COLLISIONS
ELECTRON COLLISIONS
ENERGY LEVELS
EXCITED STATES
HYDROCARBONS
ION COLLISIONS
IONS
ORGANIC COMPOUNDS
640304* - Atomic
Molecular &amp; Chemical Physics- Collision Phenomena