二乙基铍与二叔丁基铍热解机理的理论计算

考虑了各种可能的自由基和多渡态裂解反应通道，采用分子体系第一性原理计算研究了二乙基铍与二叔丁基铍单分子热解机理．分别用B3LYP、CCSD(T)和G3B3研究了分子裂解反应的势能面，给出了各反应物、产物和过渡态的几何结构、振动频率和相对能量．结果显示从热力学角度，对于上述两个分子，其主要的热解均是通过协同消除的过渡态反应而进行的．分析了这两个分子热解势能面的差 异，并计算了相关反应通道的反应焓变和反应速率常数．

Theoretical Study on Dissociation Mechanisms of Di-ethyl Berylliums and Di-t-butyl Berylliums

The potential energy surfaces (PES) of unimolecular dissociation reactions for di-ethyl beryl-lium and di-t-butyl beryllium are investigated by B3LYP, CCSD(T), and G3B3 approaches. Possible reaction pathways through either the radical or transition state (TS) of the molecules are considered. The geometries, vibrational frequencies and relative energies for various sta-tionary points are determined. From the study of energetics, the TS pathways arising from concerted molecular eliminations are indicated to be the main dissociation pathways for both molecules. The PES differences of the dissociation reactions are investigated. The activa- tion energies and rate constants will be helpful for investigating the predictive ability of the reaction in further theoretical and experimental research.