Theoretical Study On The Coordination Of Uranyl Ions With Five-membered Oxygen/Nitrogen Group Heterocyclic Schiff Base Ligands Based On Anthracene/Acridine

Uranium and other actinides are radioactive,which has brought great harm to human body and the environment,at the same time,it increases the difficulty of experimental research.By means of quantum chemical calculation,some problems that are difficult to be solved in experiments can be solved.At present,schiff base ligands containing anthracene ring and acridine ring are rare,and schiff base ligands formed by combination of anthracene ring or acridine ring and five-membered oxygen/nitrogen group heterocycles are even rarer.According to the properties of anthracene,acridine,as well as the schiff base,we designed a series new tetradentate schiff base ligands named N,N'-bis(2-five-membered heterocyclidene)-1,8-anthradiamines(BFHADAs)and pentaedentate schiff base ligands named N,N'-bis(2-five-membered heterocyclidene)-1,8-acridine-diamines(BFHADDAs).Each of these ligands contains an anthracene or acridine,and two five-membered heterocycles with nitrogen family nonmetal elements(N,P,As)or oxygen family nonmetal elements(O,S,Se,Te).Then,the density functional theory(DFT)was used to calculate the ligands and their complexes with uranyl ions.Five kinds of Uranyl-BFHADA complexes containing heterocyclic atoms N,S,As,Se and Te,respectively,and six kinds of Uranyl-BFHADDA complexes containing heterocyclic atoms N,O,S,As,Se and Te,respectively,were obtained.Because the energies were not converged,the optimal structures of Uranyl-BFHADA complexes containing heterocyclic atoms O and P and Uranyl-BFHADDA complex containing heterocyclic atoms P was not obtained.After that,the geometric configuration,frontier orbital energy and related parameters,orbital composition,Wiberg bond order,molecular energy,molecular dipole moment,electronic localization function and infrared spectra of the eleven complexes were calculated and analyzed.The results show that the frontier orbital energies of the obtained Uranyl-BFHADA complexes and Uranyl-BFHADDAs complexes were close to these of uranyl ions and their energy differences were less than 6eV,which meant that they satisfy the principle of energy proximity.So the coordination reactions between these ligands and uranyl ions were allowed.It was found that the Uranyl-BFHADA complexes were more stable than Uranyl-BFHADDA complexes when they had the same heterocyclic atoms.These results could provide an important theoretical basis and great significance for the future study of schiff base ligands containing anthracene ring or acridine ring and five-membered heterocycles,as well as the coordination of N,O,S,As,Se,Te and other elements with uranyl ions.In the first chapter of this paper,the background and significance of the research on Uranyl-BFHADA complexes and Uranyl-BFHADDA complexes were described,and the research contents and related schemes were determined.In the second chapter,we introduced the research methods of the correlation density functional(DFT),the quantum chemistry calculation software Gaussian 09 and the wave function analysis software Multiwfn.The third chapter mainly described the calculation model,calculation method,various property parameter data analysis and calculation result summary of BFHADA ligands and their complexes with uranyl.In chapter 4,the calculation model,calculation method,data analysis of various property parameters and calculation results of BFHADDA ligands and their complexes with uranyl were discussed.In the fifth chapter,we summarized the research contents and results of this paper and provided the research direction and prospect for the future research work.