Theoretical Study On The Coordination Selectivity Of Chiral Asymmetric Uranyl-salophen Complexes Based On Quantum Mechanics

Based on quantum mechanics,the theoretical calculation of molecular simulation for complexes containing radioactive elements is carried out,and the characteristic parameters of some complex molecules which difficult to get through experiments are solved.In recent years,the synthesis of asymmetric uranyl-salophen complexes has become a very important research field.More and more attention has been paid to the synthesis and application of new coordination compounds.At the same time,the coordination selectivity and molecular recognition of chiral asymmetric uranyl-salophen complexes have become one of the hotspots of current research.This article uses Gaussian 09 software to enter the keyword "genecp" in the calculation.Molecular simulation experiments on the configuration of chiral asymmetric uranyl-salophen complexes by using the density functional theory(DFT)/B3 LYP method.The Mulliken charge,IR,UV-vis,ECD,binding energy,bond order and NMR are also analyzed and discussed.Through the study of the coordination compounds formed by the coordination of R/S type asymmetric uranyl-salophen derivatives and cyclohexanamine derivatives,R type asymmetric uranylsalophen complex derivatives with good coordination selectivity and molecular recognition properties were obtained.However,the S type complex is stronger and more stable than the R type in the ability of coordination.Through the simulation and calculation of arch bridge on the configuration of the asymmetric uranyl-salophen and two chiral pyrrolidine derivatives complexes,the structure of the chiral carbon atom and the species of substituent-X on the guest have a significant influence on the structure,coordination selectivity and the polarity of the complexes.These research results provide theoretical guidance for the coordination selectivity and molecular recognition of derivatives with chiral asymmetric uranyl-salophen complexes.Firstly,it clarifies the theoretical background and significance of the research and draws up the relevant research programs.Secondly,it introduces the development history of the density functional theory and quantum computational chemistry,as well as the explanation of the function of Gaussian 09 software.Finally,a brief overview of the relevant research results of this subject is made.Research results one: In this paper,the six-membered ring lactam derivative was parallelly introduced into uranyl-salophen with R/S configuration(R/S-AUSRLs),which was used as receptors to coordinate with guests of cis/trans-methyl cyclohexylamines(cis/trans-MCHAs).Using the density functional theory (DFT)calculations at B3LYP/6-311G** level and RECP(ECP60MWB),an insight into the coordination complex of the R/S-AUSRLs with cis/trans-MCHAs was obtained.The results showed that the U atoms of receptors could coordinate with the N atoms of four kinds of cis/trans-1,2 or 1,4 guests,but the two kinds of cis/trans-1,3 guests could not be converged by the same method in the process of structural optimization due to steric hindrance,thus the cis/trans-1,3 guests could not be coordinated with the R/S-AUSRLs.The coordination actions of the R/S-AUSRLs with the guests displayed a significant difference.And the change of R-AUSRL coordination ability to the cis/trans-MCHAs was very large,but that of SAUSRL was small.Overall,the stability for the R-serial coordination complexes is higher than for the corresponding S-serial coordination complexes,and the R-AUSRL receptor has better coordination selectivity and higher molecular recognition to the guests of the cis/trans-MCHAs than the S-AUSRL receptor.However,the coordination ability of the SAUSRL with the cis/trans-MCHAs is stronger than that of R-AUSRL.The ligands a,b,c have good chemical selectivity for the asymmetric uranylsalophen derivative ligand of R/S configuration,while the ligand d does not possess.Research results two: The unit structure of polyurethane insulation materials with the best performance in international was parallelly introduced into asymmetric uranyl-salophen containing benzene methyl branched.The asymmetric uranyl-salophen derivative receptor with arch bridge configuration was obtained,and then coordinated with 9 kinds of double chiral dihydropyrrole derivatives.The B3 LYP method of density functional theory(DFT)is used to carry out theoretical calculation.The basis set includes 6-311G** and the quasi relativistic pseudopotential(ECP60MWB)used by uranium atom,and 9 kinds of complexes with three configurations including(R,R),(R,S)and(S,S)have been formed.Their geometric configurations,bond lengths,bond angles,frontier molecular orbitals,energy gaps,vibrational frequencies,binding energies and bond order data have been analyzed and discussed.The results show that during the coordination of the asymmetric uranyl-salophen of the arch bridge with double chiral dihydropyrrole derivatives,with the decrease of the atomic radius of the substituent-X,the coordination selectivity of the receptor to the guest is also gradually enhanced.These results provide theoretical guidance for the coordination selectivity and molecular recognition of asymmetric uranyl-salophen derivatives and dihydropyrrole derivatives.In the end,the content of the article is summed up,the significance of the relevant research results provides the prospect and direction for the future research.