Study On Construction And Properties Of Anion-Coordination-Based(‘aniono’) Grids And Double Helicates

Comparedtotheflourishinmetal-coordination-drivenassembly,anion-coordination-driven assembly（ACDA）is far less developed,yet it provides an alternative efficient approach to well-defined structures.In this paper,we design and synthesize of a C₂-symmetric bis-tris（urea）ligand with the p-xylylene linker,which assembles with phosphate anion to form A_2nn L_2n（A=anion,L=ligand;n=1 or 2）‘Aniono’-supramolecularassemblies.Theconstructionandpropertiesof‘Aniono’-supramolecular assemblies were further studied.This is of great significance to Anion-Coordination-Driven Assembly（ACDA）.This paper is divided into three chapter,which mainly introduce the following contents.The first chapter is the introduction,which briefly introduces the origin and development of supramolecular chemistry,the construction and transformation of supramolecular structure based on metal coordination,the general situation of urea receptor and the development of assembly,as well as the purpose and significance of this paper.In the second chapter,we design and synthesize a C₂-symmetric bis-tris（urea）ligand with the p-xylylene linker,which assembles with phosphate anion to form double helix and grid structures and the formation of these two structures are supported by crystal,NMR and MS.Crystal structures demonstrate the double helix is racemic and can encapsulate a TMA⁺cation.Moreover,the grid and double helicate are easily interconverted simply by changing the counter-cation.In chapter 3,the interaction between the double helix and choline derivative-methyl choline is further studied on the basis of the previous study on the double helicate assembly.Crystal structures demonstrateα-methyl choline was encapsulated in the aromatic box of double helicate through electrostatic an cation???πinteraction which could be further confirmed by HNMR,ESI-MS.The CD spectra demonstrate enantionmers ofα-methyl choline which interact with double helicate can induced perfect mirror imaged spectra.The ICD allowed determination of absolute configurations.