Excitation and ionic fragmentation of the carvone molecule (C10H14O) around the O 1s edge
| Autor: | M. O. Silva-Moraes, Alexsandre F. Lago, L. H. Coutinho, Sergio Pilling, Cecilia Veronica Nunez, G. G. B. de Souza, R. B. de Castilho, C.A. Lucas, A. C. F. Santos |
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| Rok vydání: | 2014 |
| Předmět: |
Radiation
Chemistry Photodissociation Analytical chemistry Photoionization Condensed Matter Physics Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Ion Fragmentation (mass spectrometry) Excited state Ionization Mass spectrum Molecule Physical and Theoretical Chemistry Spectroscopy |
| Zdroj: | Journal of Electron Spectroscopy and Related Phenomena. 192:61-68 |
| ISSN: | 0368-2048 |
| Popis: | The electronic excitation and associated ionic dissociation of the carvone molecule have been studied around the oxygen 1s edge, using synchrotron radiation and time-of-flight techniques. Photoabsorption spectrum (total ion yield) and mass spectra have been obtained in the range between 520 and 545 eV. For the sake of comparison, carvone mass spectra have also been obtained following valence (21.21 eV) and core (carbon 1s) ionization. Fragmentation of the molecule is seen to be greatly enhanced following core excitation. Around the oxygen 1s edge, we observe an extensive fragmentation of the molecular skeleton, as exemplified by the appearance of several previously unreported ions: H + , H 2 + , CH + , CH 2 + and CH 3 + , which are not formed at low energies. A maximum is observed at 536 eV photon energy in the relative intensity of the oxygen-containing ions O + , O 2+ and OH + , as an evidence for the existence of site-selective fragmentation of the carvone molecule excited around the O 1s edge. Absolute values for the photoionization and photodissociation cross sections were estimated using the molecular additive rule. |
| Databáze: | OpenAIRE |
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