Dimeric product formation in the self-reaction of small peroxy radicals using synchrotron radiation vacuum ultraviolet photoionization mass spectrometry.
Chemosphere
; 363: 142846, 2024 Sep.
Article
en En
| MEDLINE
| ID: mdl-39025306
ABSTRACT
Peroxy radicals (RO2) are key reactive intermediates in atmospheric oxidation processes and yet their chemistry is not fully unraveled. Little is known about their structures and the structures of the dimeric products (ROOR) in the self-reaction of small RO2, which are among the most abundant RO2 in the atmosphere. The product branching ratios of ROOR and their atmospheric roles are still in controversy. Here, the self-reaction of propyl peroxy radicals (C3H7O2), a typical small RO2 radical in the atmosphere, has been studied using synchrotron radiation vacuum ultraviolet photoionization mass spectrometry. Both radical (C3H7O) and closed-shell molecular (C3H6O, C3H7OH, C3H7OOC3H7) products in the self-reaction are observed in photoionization mass spectra and their elusive isomers are definitely identified in mass-selected photoionization spectra. Three isomers of the C3H7OOC3H7 dimeric products, R1OOR1, R1OOR2, and R2OOR2 (R1 and R2 represent 1-C3H7 and 2-C3H7, respectively), as well as their complex structures have been determined for the first time. Kinetic experiments are performed and compared with chemical simulations to reveal the sources of specific products. The branching ratio of the C3H7OOC3H7 dimeric channel is measured at 10 ± 5%. This work demonstrates that the dimeric product formation in the self-reaction of small RO2 radicals is non-negligible and should provide valuable new insight into atmospheric modelling.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Espectrometría de Masas
/
Sincrotrones
Idioma:
En
Revista:
Chemosphere
Año:
2024
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
Reino Unido