Influence of atmospheric nucleation precursors on the isomerization of CH2SH to CH3S: A theory inves

• 作 者: JiaCao;
• 机 构: College of Chemistry & Chemical engineering,Yan'an University,Shaanxi 716000,China
• 出 处: 第十二届全国量子化学会议
• 发表日期: 2014年期

　　Atmospheric nucleation precursors may participate in the atmospheric oxidation process and thereby change the atmospheric reaction mechanism.The isomerization of CH2SH to CH3S in the absence and presence of atmospheric nucleation precursors(H2O,HCOOH and H2SO4)has been investigated at the G3XMP2//B3LYP/6-311+G(3df,2p)level.It is shown that the barrier heights for isomerization are 28.74,6.45,12.96 and 19.23 kcal·mol-1,when the isomerization are performed in gas phase and with sulfur acid,water and formic acid as catalyst,respectively.The calculated rate constants of the isomerization using the transition state theory with the wigner tunneling correction over the temperature range of 298~800 K.The rate constant of isomerization catalyzed by sulfur acid is 1.46×103 times at 298 K larger than that in gas phase.Sulfur acid catalyzed isomerization is expected to be favorable under atmospheric condition.Moreover,topology analysis has been performed to characterize the nature of interactions in the isomerization.Enthalpies of formation(fH(θ)298 K),entropies(S(θ)298 K),and heat capacities(Cp,298~800 K)for all the stabilized species have been calculated using CBS-QB3 method.