Journal Article

FZJ-2021-04152

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png A structure activity relationship for ring closure reactions in unsaturated alkylperoxy radicals

Vereecken, L. (Corresponding author)FZJ* ; Vu, G. ; Wahner, A.FZJ* ; Kiendler-Scharr, A.FZJ* ; Nguyen, H. M. T. (Corresponding author)

2021
RSC Publ. Cambridge

This record in other databases:    

Please use a persistent id in citations: http://hdl.handle.net/2128/28937  doi:10.1039/D1CP02758A

Abstract: Terpenoids are an important class of multi-unsaturated volatile organic compounds emitted to the atmosphere. During their oxidation in the troposphere, unsaturated peroxy radicals are formed, which may undergo ring closure reactions by an addition of the radical oxygen atom on either of the carbons in the C[double bond, length as m-dash]C double bond. This study describes a quantum chemical and theoretical kinetic study of the rate of ring closure, finding that the reactions are comparatively fast with rates often exceeding 1 s−1 at room temperature, making these reactions competitive in low-NOx environments and allowing for continued autoxidation by ring closure. A structure–activity relationship (SAR) is presented for 5- to 8-membered ring closure in unsaturated RO2 radicals with aliphatic substituents, with some analysis of the impact of oxygenated substituents. H-migration in the cycloperoxide peroxy radicals formed after the ring closure was found to be comparatively slow for unsubstituted RO2 radicals. In the related cycloperoxide alkoxy radicals, migration of H-atoms implanted on the ring was similarly found to be slower than for non-cyclic alkoxy radicals and is typically not competitive against decomposition reactions that lead to cycloperoxide ring breaking. Ring closure reactions may constitute an important reaction channel in the atmospheric oxidation of terpenoids and could promote continued autoxidation, though the impact is likely to be strongly dependent on the specific molecular backbone.

---

Contributing Institute(s):

1. Troposphäre (IEK-8)

Research Program(s):

1. 2111 - Air Quality (POF4-211) (POF4-211)

Appears in the scientific report 2021

---

Database coverage:
; ; ; Allianz-Lizenz / DFG ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; IF < 5 ; JCR ; National-Konsortium ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---