jz1c00448_si_011.mp4 (14.8 MB)
Directional Proton Transfer in the Reaction of the Simplest Criegee Intermediate with Water Involving the Formation of Transient H3O+
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posted on 2021-03-30, 20:16 authored by Jinfeng Liu, Yanqing Liu, Jinrong Yang, Xiao Cheng Zeng, Xiao HeThe
reaction of Criegee intermediates with water vapor has been
widely known as a key Criegee reaction in the troposphere. Herein,
we investigated the reaction of the smallest Criegee intermediate,
CH2OO, with a water cluster through fragment-based ab initio molecular dynamics simulations at the MP2/aug-cc-pVDZ
level. Our results show that the CH2OO–water reaction
could occur not only at the air/water interface but also inside the
water cluster. Moreover, more than one reactive water molecules are
required for the CH2OO–water reaction, which is
always initiated from the Criegee carbon atom and ends at the terminal
Criegee oxygen atom via a directional proton transfer process. The
observed reaction pathways include the loop-structure-mediated and
stepwise mechanisms, and the latter involves the formation of transient
H3O+. The lifetime of transient H3O+ is on the order of a few picoseconds, which may impact
the atmospheric budget of the other trace gases in the actual atmosphere.