Title: | Molecular mechanism for rapid autoxidation in alpha-pinene ozonolysis |
Author(s): | Iyer S; Rissanen MP; Valiev R; Barua S; Krechmer JE; Thornton J; Ehn M; Kurten T; |
Address: | "Aerosol Physics Laboratory, Tampere University, Tampere, FI-33101, Finland. siddharth.parameswaraniyer@tuni.fi. Aerosol Physics Laboratory, Tampere University, Tampere, FI-33101, Finland. matti.rissanen@tuni.fi. Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki, FI-00014, Finland. Tomsk State University, 36 Lenin Avenue, Tomsk, 634050, Russia. Aerosol Physics Laboratory, Tampere University, Tampere, FI-33101, Finland. Aerodyne Research, Inc., Billerica, MA, 01821, USA. Department of Atmospheric Science, University of Washington Seattle, Washington, WA, 98195, USA. Institute for Atmospheric and Earth System Research (INAR/Physics), University of Helsinki, P.O. Box 64, Helsinki, FI-00014, Finland. Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki, FI-00014, Finland. theo.kurten@helsinki.fi" |
DOI: | 10.1038/s41467-021-21172-w |
ISSN/ISBN: | 2041-1723 (Electronic) 2041-1723 (Linking) |
Abstract: | "Aerosol affects Earth's climate and the health of its inhabitants. A major contributor to aerosol formation is the oxidation of volatile organic compounds. Monoterpenes are an important class of volatile organic compounds, and recent research demonstrate that they can be converted to low-volatility aerosol precursors on sub-second timescales following a single oxidant attack. The alpha-pinene + O(3) system is particularly efficient in this regard. However, the actual mechanism behind this conversion is not understood. The key challenge is the steric strain created by the cyclobutyl ring in the oxidation products. This strain hinders subsequent unimolecular hydrogen-shift reactions essential for lowering volatility. Using quantum chemical calculations and targeted experiments, we show that the excess energy from the initial ozonolysis reaction can lead to novel oxidation intermediates without steric strain, allowing the rapid formation of products with up to 8 oxygen atoms. This is likely a key route for atmospheric organic aerosol formation" |
Notes: | "PubMed-not-MEDLINEIyer, Siddharth Rissanen, Matti P Valiev, Rashid Barua, Shawon Krechmer, Jordan E Thornton, Joel Ehn, Mikael Kurten, Theo eng Research Support, Non-U.S. Gov't England 2021/02/11 Nat Commun. 2021 Feb 9; 12(1):878. doi: 10.1038/s41467-021-21172-w" |