Theoretical Study On The Coordination And Enantioselectivity Of Asymmetric Uranyl-Salophen With Chiral Organophosphorus Pesticide Moleculars

The design of novel uranyl-Salophen is very important for the identification and separation of chiral compounds.The guest of this article are chiral organophosphorus pesticide molecules.Its enantiomers generally have similar structures and physical and chemical properties,but their biological activities are quite different.When one enantiomer plays a positive role,the other enantiomers is often the opposite.Therefore,it is of far-reaching significance to design a new type of uranyl-Salophen receptor molecule to selectively recognize and separate the enantiomers of chiral organophosphorus pesticide molecules.This paper designed a new type of rigid asymmetric ligand based on density functional theory（DFT）which was named 2-（（1Z,9Z）-9-（2-hydroxyphenyl）-3,5,6,8-Tetrahydrobenzo[h][1,4,7,10]dioxadiaz epine-2-yl）-5-methoxyphenol（abbreviated as HTDM）,the ligand contained a bridge-like structure with a methoxy group on one side,so HTDM was a rigid asymmetric ligand.Then HTDM was coordinated with uranyl to design a new type of rigid asymmetric oxygen-substituted uranyl-Salophen receptor molecule（abbreviated as Uranyl-HTDM）.The main content of the article was to use Uranyl-HTDM as the receptor molecule with the chirality organophosphorus pesticide guest molecule R/S-malathions（R/S-MLTs）and R/S-hydrocarbophos（R/S-ICPs）carried out simulated coordination and calculations on the level of density functional theory（DFT）,which mainly included the geometric configuration of Uranyl-HTDM receptor molecule and receptor-guest complexes,Mayer bond order,electron density difference maps,localized orbital locator figures,frontier molecular orbital energy,infrared spectrum,and Gibbs free energy.We discussed and summarized the results in detail.The first part of the research of this thesis is based on the theoretical level of B3LYP//RECP//def2-SVP**,and through density functional theory（DFT）calculations,the U atom and R/S-malathions in the Uranyl-HTDM receptor molecule are discussed in detail.The coordination of the three atoms S₁,O₅ and O₆ in R/S-malathions guest molecules（R/S-MLTs）is to study the enantioselective recognition mechanism of Uranyl-HTDM receptor molecules to R/S-MLTs guest molecules.The calculation results showed that the U atom in the Uranyl-HTDM receptor molecule can be coordinated with the S₁,O₅ and O₆ atoms in the R/S-MLTs guest molecule.In order to distinguish between the coordination and non-coordination atoms,the Coordination atoms in R/S-MLTs guest molecules were labeled S₁,O₅ and O₆,respectively.After calculation and analysis,toluene is an ideal separation solvent,with the largestΔG change value,and the enantioselectivity coefficient is 99.55%.The second part of the main research content is to discuss the coordination mode of Uranyl-HTDM receptor molecule and R/S-isocarbophos guest molecules（R/S-ICPs）to study the enantioselective recognition mechanism of Uranyl-HTDM receptor molecule to R/S-ICPs guest molecules.The results showed that the U atom in the Uranyl-HTDM receptor molecule could coordinate with the S₁,O₅ and N₃ atoms in the R/S-ICPs guest molecules.Also in order to distinguish between coordination and non-coordination atoms,the coordination atoms in the guest molecules of R/S-ICPs are marked as S₁,O₅ and N₃,respectively.The calculation results showed that acetone solvent is an ideal solvent for the separation of enantiomers of R/S-ICPs,with the largest change inΔG and the enantioselectivity coefficient is 93.02%.