6,7LiX(X=H, D, T)_H2O潮解反应过程中氢同位素效应：量子化学研究

H isotope effects in 6, 7LiX (X=H, D, T)+H2O deliquescence reactions: A quantum chemistry study

摘要:

采用MP2方法对LiD/LiH/LiT+H2O反应机制进行了理论研究。计算获得的焓变化和反应速率常数与实验数据和其他理论值一致。研究结果表明LiD+H2O反应存在两个反应通道，通道1是主要的反应通道。虽然反应中同位素键发生破裂，但是动力学同位素效应不是非常明显，这与主级同位素效应的理论极大值不同。在动力学同位素效应的贡献中ηvib>ηrot>ηtun>ηpot>ηtrans，这表明同位素效应的主要贡献来自振动因子。

Abstract:

We perform theoretical investigation on mechanisms of LiD/LiH/LiT+H2O reactions with second order perturbation theory (MP2). Calculations of enthalpy change and reaction rate constant are in agreement with experimental data and other theoretical values. Results show that two reaction channels exist for LiD+H2O reaction, channel 1 is the main reaction channel. Kinetic Isotope Effect (KIE) is not so large however fracture of isotope bond takes place in the reaction, which is noticeably different from theoretical maximums of primary isotope effect. Individual contributions of KIE effect are listed as follows ηvib>ηrot>ηtun>ηpot>ηtrans, indicating that main contribution of isotope effect results from vibration factor.