中文摘要：

采用密度泛函理论的COSMO模型模拟了在DMF溶剂中三种不同体积的钯配体Pd（PR3）n （n=1,2） （PR3=PH3, PMe3, PtBu3）与溴苯氧化加成的反应过程. 对比双配体Pd（PR3）2的裂解能以及双配体钯Pd（PR3）2和单配体钯Pd（PR3）氧化加成过程的能垒；结果表明，小体积的配体PH3和PMe3是以双配位的形式参加氧化加成过程的，而较大体积的配体PtBu3是以单配位钯的形式参加氧化加成过程的.

英文摘要：

The process and mechanism of the ligand volume controlled Pd（PR3）2 （PR3=PH3, PMe3, and PtBu3） oxidative addition with aryl bromide were investigated, using density functional theory method with the conductor-like screening model. Association pathway and dissocia-tion pathway were investigated by the comparison of several energies. The cleavage energy of Pd（PR3）2 complex was calculated, as well as the oxidative addition reaction barrier energy of Pd（PR3）n （n=1,2） with aryl bromide in N,N-dimethylformamide solvent. This study proved that the ligands volume possessed a great impact on the mechanism of oxidative addition： less bulky ligand palladium associated with aryl bromide via two donor ligands,but larger bulky ligand palladium coordinated via monoligand.