Reactions with Criegee intermediates are the dominant gas-phase sink for formyl fluoride in the atmosphere  

作　　者：Yu Xia Bo Long Ai Liu Donald G.Truhlar 

机构地区：[1]College of Materials Science and Engineering,Guizhou Minzu University,Guiyang 550025,China [2]Department of Chemistry,Chemical Theory Center,and Minnesota Supercomputing Institute,University of Minnesota,Minneapolis,MN 55455-0431,United States

出　　处：《Fundamental Research》2024年第5期1216-1224,共9页自然科学基础研究（英文版）

基　　金：supported in part by the National Natural Science Foundation of China(42120104007 and 41775125);by Guizhou Provincial Science and Technology Projects,China(CXTD[2022]001 and GCC[2023]026);by the Science and Technology Foundation of Guizhou Provincial Department of Education,China(KY[2021]014 and KY[2021]107);supported in part by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences under Award DE-SC0015997.

摘　　要：Atmospheric oxidation processes are of central importance in atmospheric climate models.It is often considered that volatile organic molecules are mainly removed by hydroxyl radical;however,the kinetics of some reactions of hydroxyl radical with volatile organic molecules are slow.Here we report rate constants for rapid reactions of formyl fluoride with Criegee intermediates.These rate constants are calculated by dual-level multistructural canonical variational transition state theory with small-curvature tunneling(DL-MS-CVT/SCT).The treatment contains beyond-CCSD(T)electronic structure calculations for transition state theory,and it employs validated density functional input for multistructural canonical variational transition state theory with small-curvature tunneling and for variable-reaction-coordinate variational transition state theory.We find that the M11-L density functional has higher accuracy than CCSD(T)/CBS for the HC(O)F+CH2OO and HC(O)F+anti-CH_(3)CHOO reactions.We find significant negative temperature dependence in the ratios of the rate constants for HC(O)F+CH2OO/anti-CH_(3)CHOO to the rate constant for HC(O)F+OH.We also find that different Criegee intermediates have different rate-determining-steps in their reactions with formyl fluoride,and we find that the dominant gas-phase removal mechanism for HC(O)F in the atmosphere is the reaction with CH2OO and/or anti-CH_(3)CHOO Criegee intermediates.

关 键 词：Atmospheric oxidation capacity Criegee intermediates Formyl fluoride Reaction kinetics CCSDT(Q)/CBS calculations 

分 类 号：O62[理学—有机化学]