Synthesis Of Pillar[5]arene-based[1]rotaxane And Construction Of Pillar[5]arene-based Supramolecular Polymer

Pillar[n]arens are one kind of macrocyclic molecule,which consist of hydroquinone units linked by methylene bridges in the para position.It is widely used in the fields of artificial transmembrane channels,chemical and physical response materials,drug transport and release,sensing and detection.They have good binding ability with many guest molecules,making pillar[n]arenes and their derivatives extremely easy to form rotaxane or pseudo-rotaxane structures,which are used in the construction of molecular machines.Based on the identification of the host and the guest,when certain conditions are met,the pillar[n]arene and the guest molecule can self-assemble to form supramolecular polymer.In this paper,a series of pillar[5]arene-based[1]rotaxanes and pseudo[1]rotaxanes were designed and synthesized.Two kinds of pillar[5]arene-based supramolecular polymers were constructed through host-guest interactions,and their various properties were studied.The main research contents are as follows:1.Through the reaction of monoamide functionalized pillar[5]arene with ferrocenecarboxylic acid,six ferrocene-based pillar[5]arene compounds were conveniently obtained.In the formation of[1]rotaxane,the key role is the length of the alkyl chain in this process.Only when the number of carbon on the N-aminoalkyl chain is larger than three,can the formation of[1]rotaxane occur.The structures of the synthesized compounds were characterized by NMR,IR and HR-MS spectroscopy,and the crystal structures of the two compounds were determined by X-ray single crystal diffraction.Moreover,these[1]rotaxanes showed electrochemically reversible properties due to the ferrocene unit on them.2.A series of ferrocene-based pillar[5]arene dimers were synthesized according to"threading-followed-by-stoppering".A new supramolecular polymeric material was efficiently constructed via orthogonal host-guest interaction between the ferrocene-bridged pillar[5]arene dimer 30 and the symmetric long-chain guest G1 containing two cyano groups and hydrogen bonding interaction from the amide groups,and characterized by NMR,dynamic laser scattering,and scanning electron microscope,and viscosity measurement.Supramolecular materials were further studied afterwards.It can catalyze H2O2 to generate·OH through Fenton-like reaction,which can be detected by TMB discoloration reaction.OH has an ability to damage cellular constituents effectively,meanwhile,cancer cells exhibit much higher levels of H2O2 than normal cells,which suggested its potential application in tumor therapy through chemodynamic therapy(CDT),it can be used to prepare nano anti-tumor drugs.3.Based on the construction of pseudo[1]rotaxane,a series of Schiff base-bridged pillar[5]arene dimers were synthesized.These compounds were characterized by 1H NMR,13C NMR and IR.2D NOESY showed that the pillar[5]arene dimers containing N-aminoalkyl chains with more than two-CH2-units existed in an interlocking structure in CDCl3.Due to the Schiff base structure,they has a strong coordination effect on some transition metals.The pillar[5]arene dimer 60 and the neutral tritopic guests G2 with cyano and triazole groups are self-assembled to form a networked supramolecular polymer.