De-excitation electron spectroscopy of core-excited methyl formate

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7014806

Ji, De

The electron-electron coincidence (e, 2e) technique has been used to measure the autoionization (Auger) electrons emitted flowing the excitation of acore electron that has been promoted to a selected molecular orbital in methyl formate. The de-excitation spectra from the core-excited neutral molecules have been studied and analyzed not only with theoretical calculations by also by experiment in some detail. These autoionization spectra can be separated into two parts. The higher kinetic energy part, where the core-excited electron participates in the transition, arises from participator decay. The lower kinetic energy part, where the core-excited electron remains as a spectator during the decay, arises from spectator decay. The speculator spectrum is similar to a normal Auger spectrum. In studying of the spectator decay, the author has compared oxygen spectrum in methyl formate with the spectra in CO, CO[sub 2], and OCS. The surprising similarities in the spectator decay of oxygen core-excited CO, CO[sub 2], and OCS reported by Carroll and Thomas is not apparent in methyl formate. The author concludes that the methyl formate is more complicated than the other three molecules, and the antibonding effect of the excited core electron is not strong enough to make the carbonyl oxygen as weakly bound in methyl formate as in CO, CO[sub 2], and OCS. In studying the participator decay, the author compared the participator decay (single-hot state) spectra obtained by the (e, 2e) coincidence technique with the photoionization spectra excited by HeI resonance line (21.22eV) and with theoretical results. They are in excellent agreement with each other. The spectra show that the excited [pi] electron is strongly localized on the carbonyl oxygen atom. The assignments of the transition for all participator decays have been made, and molecular orbital compositions have been discussed.

• Research Organization: Oregon State Univ., Corvallis, OR (United States)
• OSTI ID: 7014806
• Country of Publication: United States
• Language: English

Related Subjects

664200* -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ALKYL RADICALS
AUTOIONIZATION
CARBOXYLIC ACID SALTS
DE-EXCITATION
ELECTRON SPECTRA
ENERGY-LEVEL TRANSITIONS
FORMATES
HYDROCARBONS
IONIZATION
METHYL RADICALS
ORGANIC COMPOUNDS
PHOTOIONIZATION
RADICALS
SPECTRA