TY - JOUR
T1 - Gas phase transformation from organic acid to organic sulfuric anhydride
T2 - Possibility and atmospheric fate in the initial new particle formation
AU - Zhang, Haijie
AU - Wang, Wei
AU - Pi, Shuangqi
AU - Liu, Ling
AU - Li, Hao
AU - Chen, Yu
AU - Zhang, Yunhong
AU - Zhang, Xiuhui
AU - Li, Zesheng
N1 - Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/12
Y1 - 2018/12
N2 - New particle formation (NPF) process has been observed frequently in various environments and produces a large fraction of atmospheric aerosols. However, the chemical species participating in the nucleation as well as the corresponding nucleation mechanism in the atmosphere still remain ambiguous. Recent research by Leopold et al. shows that cycloaddition reaction of SO3 to carboxylic acids could contribute to the formation of organic sulfuric anhydride which would have lower vapor pressure compared with the corresponding carboxylic acid and hence kick-start new particle formation in the gas phase. In the present study, energy profile for the formation of 3-methyl-1,2,3-butanetricarboxylic sulfuric anhydride (MBTCSA) through the cycloaddition of SO3 to 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA) has been investigated using computational methods. As a result, such a process would be effectively barrierless for one of the terminal carboxy group and has very low energy barriers for the other two carboxy groups (0.6 and 2.8 kcal/mol, respectively), indicating the whole process is a plausible gas phase pathway to MBTCSA formation. Furthermore, by evaluating the stability of the generated atmospheric clusters through topological and kinetic analysis, interaction between atmospheric nucleation precursor with MBTCSA is found to be more thermodynamically favourable and stronger than those with sulfuric acid and MBTCA which is identified from further-generation oxidation of a-pinene. Hence MBTCSA is speculated to be a potential participator in the initial new particle formation and the further particles growth.
AB - New particle formation (NPF) process has been observed frequently in various environments and produces a large fraction of atmospheric aerosols. However, the chemical species participating in the nucleation as well as the corresponding nucleation mechanism in the atmosphere still remain ambiguous. Recent research by Leopold et al. shows that cycloaddition reaction of SO3 to carboxylic acids could contribute to the formation of organic sulfuric anhydride which would have lower vapor pressure compared with the corresponding carboxylic acid and hence kick-start new particle formation in the gas phase. In the present study, energy profile for the formation of 3-methyl-1,2,3-butanetricarboxylic sulfuric anhydride (MBTCSA) through the cycloaddition of SO3 to 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA) has been investigated using computational methods. As a result, such a process would be effectively barrierless for one of the terminal carboxy group and has very low energy barriers for the other two carboxy groups (0.6 and 2.8 kcal/mol, respectively), indicating the whole process is a plausible gas phase pathway to MBTCSA formation. Furthermore, by evaluating the stability of the generated atmospheric clusters through topological and kinetic analysis, interaction between atmospheric nucleation precursor with MBTCSA is found to be more thermodynamically favourable and stronger than those with sulfuric acid and MBTCA which is identified from further-generation oxidation of a-pinene. Hence MBTCSA is speculated to be a potential participator in the initial new particle formation and the further particles growth.
KW - Atmospheric nucleation precursor
KW - Evaporation coefficient
KW - New particle formation
KW - Organic sulfuric anhydride
KW - Reaction mechanism
UR - http://www.scopus.com/inward/record.url?scp=85052286361&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2018.08.074
DO - 10.1016/j.chemosphere.2018.08.074
M3 - Article
C2 - 30165277
AN - SCOPUS:85052286361
SN - 0045-6535
VL - 212
SP - 504
EP - 512
JO - Chemosphere
JF - Chemosphere
ER -
