论文部分内容阅读
采用abinitio HF,MP2方法和密度泛函理论方法,对Pd(0),Pd(Ⅰ)双核配合物Pd2L2和Pd2L2X2(L=Me2PCH2PMe2;X=F,Cl,Br,I,H)的几何结构和电子结构进行了研究.研究表明Pd2L2中Pd原子间的相互作用主要来自电子相关效应,Pd2L2X2中Pd原子间的相互作用则主要来自d轨道的成键作用.MP2方法和局域泛函Xα方法能对两类配合物的几何结构给予准确的描述.在Pd2L2中,Pd原子的4d电子组成一一对应的成键、反键轨道,轨道作用相互抵消使Pd原子间仅存在微弱的相互作用.X原子与Pd2L2的作用使Pd—Pd反键轨道电子占据数减少,成键作用加强.两类配合物的Pd—Pd键长与NAO键级之间存在很好的线性关系.还对Pd2L2和Pd2L2X2的低占据电子激发态进行了含时密度泛函理论计算,分析不同配合物的电子跃迁特征,并就卤素配体对Pd2L2X2光谱性质的影响进行了讨论.
The geometries of the Pd (0), Pd (Ⅰ) binuclear complexes Pd2L2 and Pd2L2X2 (L = Me2PCH2PMe2; X = F, Cl, Br, I, H) were determined by ab initio HF, MP2 and density functional theory The results show that the interaction between Pd atoms in Pd2L2 mainly comes from the electron-related effect, and the interaction between Pd atoms in Pd2L2X2 mainly comes from the d-orbital bonding.The MP2 method and the local Xα method In the Pd2L2, the 4d electrons of Pd atoms form a one-to-one bond, antibonding orbital interactions that cancel each other out, leaving only weak interaction between the Pd atoms.X The interaction between Pd2L2 and Pd2L2 reduced the occupied number of Pd-Pd antibonding orbital and enhanced the bond formation.The Pd-Pd bond lengths and NAO bond lengths of the two complexes were in good linear relationship.For Pd2L2 and Pd2L2X2 The low-occupied electron excited states were calculated by time-dependent density functional theory, and the electronic transition characteristics of different complexes were analyzed. The influence of halogen ligands on the spectral properties of Pd2L2X2 was also discussed.