气相VO(∑^+)与CH_3OH(~1A′)分子自旋禁阻反应C-H,O-H键活化机理的理论研究

Theoretical study of the mechanism for C-H, O-H bond activation in spin-forbidden reaction between VO and CH_3OH in the gas phase

采用密度泛函理论(DFT)B3LYP与CCSD方法研究了二重态和四重态势能面自旋禁阻反应VO(∑+)活化CH3OH(1A′)分子C–H,O–H键的微观机理.通过自旋-轨道耦合的计算讨论了势能面交叉点和可能的自旋翻转过程.在MECP处,四重态和二重态间的旋轨耦合常数为131.14cm?1.自旋多重度发生改变,从四重态系间穿越到二重态势能面形成中间体2IM1,导致反应势能面的势垒明显降低.

The mechanism of the spin-forbidden reaction VO （Σ＋） ＋ CH3OH （JA′） on quartet and doublet potential energy surfaces （PESs） has been investigated by DFT of B3LYP and CCSD. Crossing points between the different potential energy surfaces and the possible spin inversion process are discussed by spin-orbit coupling （SOC） calculations. The values of the SOC constants at MECP are 131.14 cm^-1 between quartet and doublet PESs. The intersystem crossing （ISC） between different quartet and which obviously reduce energy barriers. doublet PESs would occur and has been produced 2^IM1,