YS^+(~1Σ^+,~3Φ)与COS气相反应YS^++COS→YS_2^++CO的理论研究(英文)

Theoretical Study on Gas-Phase Reaction of YS^+(~1Σ^+,~3Φ) with COS of YS^++COS→YS_2^++CO

采用密度泛函理论B3LYP方法研究了硫化钇离子YS+(1Σ+,3Φ)与硫转移试剂COS在气相中的反应:YS++COS→YS+2+CO. 在单重基态和三重激发态势能面上都找到了四条反应通道. 但是除一条反应通道之外,其它的反应机理和几何结构变化趋势在不同的势能面上有很大不同. 实验中生成YS+2所表现出的吸热特征来自于在基态反应中的三条通道(A, B和C), 其活化势垒分别为28.3、140.5和120.2 kJ·mol-1. 计算结果表明硫转移反应没有双态反应活性, 因此产物YS+2在低能量区的放热特征是由于基态反应物中还混有残留的激发态YS+.

The gas-phase reactions of YS＋ （1Σ＋, 3Φ） with an S-transfer reagent （COS）, YS＋＋COS→YS2＋＋CO, were studied using density functional theory at the B3LYP/6-311＋G＊ level. Four parallel reaction pathways were identified on both the ground- and excited-state surfaces. The mechanisms and the geometrical change trends on the different surfaces are quite different, except in the case of one reaction channel. The experimentally observed endothermic feature of the formation of YS2＋ can be attributed to three reaction paths, A, B, and C, with calculation barriers of 28.3, 140.5, and 120.2 kJ mol-1, respectively, on the ground singlet surface. Our calculation results show that the title reactions have no two-state reactivity and the exothermic feature of the YS2＋ cross-section observed in the experiments is attributed to reaction of the residual excited-state of YS＋ in the reactants.