Synthesis And Properties Of Pseudorotaxane And Rotaxane Based On Cryptand And Pillar[5]arene

Molecular machines,refer to assemblies constructed by molecules,which can response to external stimuli and show movement like machines in molecular level.Pseudorotaxane and rotaxane are basic models for study molecular machines.Pseudorotaxane is constructed by thread component and cycle component,in solution thread component and cycle component could form host-guest complex through intermolecular interaction.The thread part is refered to guest,while the cycle component is refered to host.Rotaxane is developed from pseudorotaxane.For rotaxane,on both ends of the thread component there are the stoppers,which are big enough to prevent the cycle component from sliding down.The research for pseudorotaxne and rotaxane could help people deeply understand structures and movement behaviors of molecular machines.On the basis of those research,we can design and synthesize more complicated and functional molecular machines.For now,the research for pseudorotaxane and rotaxane are focus on the design of new type of movement behaviors,the development of new topological structure,the discovery of new hostguest interaction and application.According to the above research frame,the research content of this dissertation mainly includes the following aspects:In chapter 1,the development of supramolecular chemistry and basic concepts related to supramolecular chemistry and molecular machines were summarized.Then we introducing pseudorotaxane type and rotaxane type molecular machines based on crown ether,pillararene and cryptand.Finally,the potential applications of pseudorotaxane type and rotaxane type molecular machines are introduced in supramolecular polymer,small molecule gel,nano valve,molecular muscle,supramolecular catalysis,In chapter 2,a switchable[2]rotaxane based on the pyridinediamide crown ether macrocycle and the thread bearing phosphine oxide,urea,and dibenzylammonium functional groups was developed successfully,in which the macrocycle could move along the thread as a bistable or tristable molecular shuttle under external stimuli.Moreover,P=O functional group,as one of three stations plays the important role in the construction of the molecular shuttle,and in the packing style of the crystals as well.In chapter 3,two pillar[5]arene-based mechanically selflocked molecules(MSMs)were constructed successfully.In the crystal,two enantiomers of MSM 1 were observed in pairs,and meanwhile,packed alternately linked by anti-syn urea groups.Conformer inversions of these two MSMs were also investigated in solvent with gradually changed polarities,and by the addition of 1,4-dicyanobutane(G)as a competitive guest.In chapter 4,by introducing 4-methylcoumarin group to the third arm of the cryptand,a fluorescent responsive BMP32C10-based cryptand host 1 was synthesized successfully.Interestingly,it was found that the cryptand 1 could undergo[2+2]photodimerization upon UV irradiation(?=365 nm),and based on the photodimerization and host-guest interaction,a new supramolecular polymer was constructed conveniently.In chapter 5,two kinds of fluorescent BMP32C10-based cryptands 1 and 2 have been developed.Cryptand 1 contains a binaphthol group,while cryptand 2 bears a coumarin group in their third arms respectively.Based on this design,novel self-assemblies constructed between cryptands 1 or 2 and basic N-heteroaromatics guests 3-6 were successfully obtained.Moreover,the threading/dethreading processes of the host-guest complexes could be well-switched by the alternate addition of acid/base,and accompanied by concurrent changes in fluorescence.In summary,this dissertation using crown ether,cryptand and pillar[5]arene as hosts constructed pseudorotaxane and rotaxane.We further studied the movement behaviors,conformation stability and stimuli stimulative responsibility of them.Our research is significant for further research.