Structures and reactivity of peroxy radicals and dimeric products revealed by online tandem mass spectrometry

Sophie Tomaz, Dongyu Wang, Nicolás Zabalegui, Dandan Li, Houssni Lamkaddam, Franziska Bachmeier, Alexander Vogel, María Eugenia Monge, Sébastien Perrier, Urs Baltensperger, Christian George, Matti Rissanen, Mikael Ehn, Imad El Haddad, Matthieu Riva

Research output: Contribution to journalArticleScientificpeer-review

2 Downloads (Pure)


Organic peroxy radicals (RO2) play a pivotal role in the degradation of hydrocarbons. The autoxidation of atmospheric RO2 radicals produces highly oxygenated organic molecules (HOMs), including low-volatility ROOR dimers formed by bimolecular RO2 + RO2 reactions. HOMs can initiate and greatly contribute to the formation and growth of atmospheric particles. As a result, HOMs have far-reaching health and climate implications. Nevertheless, the structures and formation mechanism of RO2 radicals and HOMs remain elusive. Here, we present the in-situ characterization of RO2 and dimer structure in the gas-phase, using online tandem mass spectrometry analyses. In this study, we constrain the structures and formation pathway of several HOM-RO2 radicals and dimers produced from monoterpene ozonolysis, a prominent atmospheric oxidation process. In addition to providing insights into atmospheric HOM chemistry, this study debuts online tandem MS analyses as a unique approach for the chemical characterization of reactive compounds, e.g., organic radicals.

Original languageEnglish
Article number300
Number of pages9
JournalNature Communications
Issue number1
Publication statusPublished - 2021
Publication typeA1 Journal article-refereed

Publication forum classification

  • Publication forum level 3

ASJC Scopus subject areas

  • General Chemistry
  • General Biochemistry,Genetics and Molecular Biology
  • General Physics and Astronomy


Dive into the research topics of 'Structures and reactivity of peroxy radicals and dimeric products revealed by online tandem mass spectrometry'. Together they form a unique fingerprint.

Cite this