Formation of highly excited iodine atoms from multiphoton excitation of CH3I
| Autor: | Pavle Glodic, Ágúst Kvaran, Kristján Matthíasson, Peter C. Samartzis, Meng-Xu Jiang, Greta Koumarianou |
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| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Physical Chemistry Chemical Physics. 22:4984-4992 |
| ISSN: | 1463-9084 1463-9076 |
| Popis: | Mass resolved REMPI spectra, as well as CH3+and I+ ion and photoelectron images, were recorded for two-photon resonant excitations of CH3I via s, p and d Rydberg states (CH3I**) in the excitation region of 55 700 to 70 000 cm−1. Photoelectron (PE) and ion kinetic energy release spectra (KERs) were derived from the images. The data revealed that after the two-photon resonant excitation, an additional photon is absorbed to form one or more superexcited state(s) (CH3I#), followed by branching into three pathways. The major one is the dissociation of CH3I# to form excited Rydberg states of iodine atoms (I**) along with CH3(X), a phenomenon not commonly observed in methyl halides. The second (minor) pathway involves autoionization of CH3I# towards CH3I+(X), which absorbs another photon to form CH3+ along with I/I* and the third one (minor) is CH3I# dissociation towards the ion pair, CH3+ + I−, prior to I− electron ejection. Furthermore, one-photon non-resonant dissociation of CH3I to form CH3(X) and I/I* prior to three-photon ionization of the fragments is also detected. |
| Databáze: | OpenAIRE |
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