School Of Chemistry And Molecular Engineering

Mechanically interlocked molecules have become one of the most attractive research fields in supramolecular chemistry and nanochemistry due to their exquisite topological structures and unique dynamic properties.Chemists have made significant progress in synthesizing diverse mechanically interlocked molecules,including rotaxanes,molecular knots,and catenanes,which have found important applications in areas such as artificial molecular machinery,catalysis,nanoparticle assembly,surface chemistry,and drug delivery.However,the efficient synthesis of these molecules remains a formidable challenge,and their full potential in various fields is yet to be explored.This thesis aims to exploring efficient synthesis strategies for two classic mechanically interlocked structures,trefoil knots and rotaxanes,laying the foundation for developing their potential application value.Specifically,this work will focus on two aspects.On the one hand,it will explore and develop efficient synthetic strategies for lanthanide based polymetallic templates to obtain target amide trefoil knot,and further prospect their enormous development potential in the fields of chiral catalysis,chiral recognition,chemical sensors,liquid crystals,and drug delivery;On the other hand,a series of peptide[2]rotaxanes will be constructed by combining polypeptide drugs with rotaxanes,and their potential applications in the field of biomedicine will be further explored.Overall,this thesis is structured around the following main research objectives:Chapter one provides an overview of the research progress made in the field of mechanically interlocked molecules,including the two types of interlocked molecules,molecular knots and rotaxanes.Section knots focuses on the synthesis of molecular knots using lanthanide metal templates.Common synthesis strategies using lanthanide metal templates to construct molecular knot will be discussed in detail.In section rotaxanes,we examine the common synthesis strategies used for molecular rotaxanes.The advantages and disadvantages of various synthesis strategies will be analyzed,with a particular emphasis on the metal-free template strategy employed in this thesis.Additionally,the application of rotaxanes in biomedicine will be briefly introduced.In chapter two,based on the work of a series of Ln^Ⅲcomplexes reported earlier,the ligands were reasonably designed and synthesized.Using a polymetallic template strategy based on lanthanides,we obtained the desired spirochete.Subsequent olefin metathesis reaction,followed by demetallation,a molecular trefoil knot was successfully achieved.In chapter three,we present a one-step synthesis of tripeptide-based[2]rotaxanes via previously reported a metal-free active template.Our method utilizes commercially available peptides as thread-forming components and a 24-crown-8 macrocycle to produce these otherwise inaccessible rotaxanes with yields of up to 50%.Apart from being simple and efficient,this method offers the potential for a wide range of rotaxanes with modifiable properties and versatile functionality.