Molecular Simulation And Design Of Uranium And Thorium Complexes

Uranium and thorium are important nuclides, both of them are harmful substances to enrivonmental. Thus, the extraction of uranium and thorium from the environment has received increasing attention, as well as the applications to uranium and thorium. In recent years, the asymmetric synthesis of uranyl compounds has become a very important area researching, and the new compounds synthesis and application is becoming more and more important. Thorium is separated and extracted from the environment has been widespread support and concern. At the same, in recently, the asymmetry of uranyl comlex compounds of catalytic and recognition has become a hot research. In this paper, using Gaussian 09 quantum chemical calculation software /density functional theory(DFT) / B3 LYP method, the uranium and thorium complexes optimized geometries are simulated, and its geometry, charge distribution, infrared spectroscopy, thermodynamics nature, WIBs and other characteristics of the chemical shifts are discussed and analyzed. Through the deep research in complexes which formed by Uranyl-Salophen with cyclohexenone or cyclohexenone derivative. We got the order of catalytic ability and binding of Uranyl-Salophen to cyclohexenone and cyclohexenone derivative. At thesame time, we can predict the major product in different configurations of the catalytic reaction. Through the computer simulation to the strength of complexes which formed by thorium and uranium ions, we can make a prediction to the stability of different configuration. These studies theoretically elucidate uranium and thorium formed complex in the structure and properties, and providing an important reference for further experimental studies, and make a prepare ground in further study to the structure and properties of Uranium and thorium complexes.The first chapter describes the contents and significance of the research, and briefly describes the related programs of this study, and put forward the research ideas and programs through combined with the subject content and requirements of the project proposes.The second chapter provides an overview of the density functional theory based on the background and significance, and briefly describes the history of development of quantum chemistry and the main function of Gaussian software.The third chapter unilateral benzene ring substituted uranyl-Salophen(i.e. asymmetry uranyl-Salophen) of Ligand Model cyclohexenone and derivatives formed. At the same, using Gaussian 09 quantum chemical calculation software / density functional theory(DFT)/ B3 LYP method / 6-311 G ** basis sets. Charge distribution(Mullinken distribution), infrared spectroscopy, thermodynamic properties, WIBsand the frontier molecular orbital energy were discussed and analysis to complexes of asymmetric geometry of Uranyl-Salophen with cyclohexenone and cyclohexenone derivatives. The results shown that the binding energy of asymmetry uranyl-Salophen coordinated with methyl-substituted cyclohexenone significantly more strongely than the corresponding fluorine atoms substituted cyclohexenone complexes. The binding of asymmetry Uranyl-salophen coordinated with cyclohexenone derivatives substituted in E-type more strongly than the corresponding cyclohexenone substituted in Z-type complexes. And the cyclohexenone's or cyclohexenone derivatives' s C=C double bond of complex located at the top of the configuration whose binding capacity was stronger than the corresponding C=C double bond in the down of the conformation. Thus, we can predict the major product by the complex formation, and make predictions to catalyze sites of the reaction.The fourth chapter using density functional theory(DFT) / B3 LYP /6-311 G ** next level, under vacuum model theoretical calculations and molecular simulation to the complex N, N'- bis-salicylaldehyde allyl-o-phenylenediamine complex combination of thorium(Th(BASPDA)2) which has been reported in experimental in single crystal structure. At the same time, we compared the the main parameters of the optimed of configuration with the experimental data, and found that thetheoretical and experimental values with a very high degree of agreement. What's interesting, under the same basis sets, we found the other configuration in Th(BASPDA)2 molecular, and compared and analyzed the two structure through theoretical molecular simulation.The fifth chapter using density functional theory(DFT) / B3 LYP /6-311 G ** next level, to molecular simulation for the N, N'-bis-salicylaldehyde allyl-o-phenylenediamine complex combination of uranium(U(BASPDA)2). The results indicated that the coordination complex of U(BSAPDA)2 could form two different structures with a ratio of 1:2. One was a parallel dislocation structure(PDS-U), in which the two BSAPDAs' middle benzene rings adopted a parallel dislocation with an angle of 56.64°, and the other was a staggered finger "+" structure(SFS-U), in which the two BSAPDA employed the staggered finger "+" shape. Those properties including the binding energies, charge distribution, spectral properties, thermodynamic properties, molecular orbitals, and wiberg bond indices for both PDS-U and the SFS-U, were also calculated and compared to each other. The calculated results further indicated that SFS-U has a higher stability compared to that of PDS-U, and the BSAPDA ligand coordinated more tightly to U(IV) in SFS-U complex compared to that in PDS-U complex.The sixth chapter of the thesis made a systematic research summary,and pointed out the significance of this issue, as well as follow-up workto make the prospect.