The Quantum Study Of The Bimetallic Phosphido-Bridged Complex

The prominent progress in computational transition metal chemistry has stimulated the current theoretical effort to obtain an accurate picture of the binuclear phosphido-bridged complexes. One special feature of binuclear metal-metal bonded the characters of the phosphido-bridged complexes such as the CpW(CO)2(μ-CO)(μ-PPh2)Fe(CO)3 和 CpW(CO)3(μ-PPh2)W(CO)4 , which were synthesized recently, is the influence of the metal-metal bond functions as a switch to control the reaction according to the properties of the ligand on the complex. It will be very useful to further the study of the metal-metal bond in such bimetallic phosphido-bridged complexes.In this research, the geometry structures of the binuclear phosphido bridged complexes: Cp(CO)2W(μ-PPh2)W(CO)5 and Cp(CG)3W(μ-PPh2)W(CO)5 , CpW(CO)2(μ-CO)(μ-PPh2)Fe(CO)3 and CpW(CO)3(μ-PPh2)Fe(CO)4 , the properties of the metal-metal bond wereboth employed. The purpose of this work is to study the geometry configuration, bonds nature by Quantum Chemistry and electronic density topological analysis methods. This dissertation discussed the effects of the different computation methods and basis sets on calculated the geometry of these special complexes, the metal-metal bond nature of the complexes. The rules of the breakage and formation of metal-metal bond in the complex were discussed in order to help further research in this field.Comparative study of the bimetallic phosphido-bridged complex have been performed by using the HF and DFT methods with LANL2DZ, CEP-31G and SDD basis sets with aim to investigate their molecular structures and metal-metal bonding in the complexes. The optimized results revealed that it is reasonable way to calculate the complex containing the heavy transition metal atoms with the HF and DFT methods. It is found that DFT methods can be a powerful and effective computational tool to predict structural properties of the phosphido-bridged complexes that containing heavy transition metal-metal bonds. The overall performance of the calculations at the MPW1PW91/LANL2DZ level was found to be satisfactory to reproduce the available experimental data.And we pay more attention to the investigation of the topological properties of the metal-metal bonds. In the view of quantum topology, the characteristic of W-W, W-Fe bonds was described quantitatively according to the electronic density, Laplacian for the first time. The results show the...