Premium
Mechanistic Insight into the Reaction of Organic Acids with SO 3 at the Air–Water Interface
Author(s) -
Zhong Jie,
Li Hao,
Kumar Manoj,
Liu Jiarong,
Liu Ling,
Zhang Xiuhui,
Zeng Xiao Cheng,
Francisco Joseph S.
Publication year - 2019
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201900534
Subject(s) - interface (matter) , chemistry , environmental chemistry , organic chemistry , molecule , gibbs isotherm
The gas‐phase reaction of organic acids with SO 3 has been recognized as essential in promoting aerosol‐particle formation. However, at the air–water interface, this reaction is much less understood. We performed systematic Born–Oppenheimer molecular dynamics (BOMD) simulations to study the reaction of various organic acids with SO 3 on a water droplet. The results show that with the involvement of interfacial water molecules, organic acids can react with SO 3 and form the ion pair of sulfuric‐carboxylic anhydride and hydronium. This mechanism is in contrast to the gas‐phase reaction mechanisms in which the organic acid either serves as a catalyst for the reaction between SO 3 and H 2 O or reacts with SO 3 directly. The distinct reaction at the water surface has important atmospheric implications, for example, promoting water condensation, uptaking atmospheric condesation species, and incorporating “SO 4 2− ” into organic species in aerosol particles. Therefore, this reaction, typically occurring within a few picoseconds, provides another pathway towards aerosol formation.