CH3CH2O及CH3CHOH与HO2反应机理的理论研究

Theoretical study on the reaction mechanisms of CH_3CH_2O and CH_3CHOH with HO_2

采用CCSD(T)/cc-p VTZ//B3LYP/6-311++G(2df,2p)水平上对CH_3CHOH+HO_2和CH_3CH_2O+HO_2反应体系的单、三重态反应机理进行了详细的理论研究.计算结果表明,CH_3CHOH+HO_2反应主要发生在单重态势能面上,其中四条通道均为快速自发过程;CH_3CH_2O+HO_2反应在三重态势能面上的通道CH_3CH_2O+HO_2→~3IM11→~3TS11→P11(CH_3CH_2OH+~3O_2)为动力学和热力学的优势路径.大气中CH_3CHOH比CH_3CH_2O更容易稳定存在.

The reaction mechanisms of CH3CH20 ＋ HO2 and CH3CH=O ＋ HO2 have been investigated at the CCSD （T）/ce -pVTZ//B3 LYP/6 -311 ＋ ＋ G（2df, 2p） level of theory. The single and triplet point energies a- long the minimum energy potential were calculated. The results show that the channels of CH3 CHOH ＋ HO2 on the singlet potential energy surfaces （PES） are all fast spontaneous processes, whereas that of CH3CH20 ＋ H02 proceeds as CH3CH20 ＋ HO2--＋ 3IMll --~ 3TSll --＋ Pll （CH3CH2OH ＋ 302） on the triplet PES are favorable at dynamics and thermodynamics. In the atmosphere, CH3CHOH is more stable than CH3CH20.