Studies On Metathesis Synthesis Of Pillararene-Containing Polymers And Their Host-Guest Properties

Supramolecular chemistry plays an important role as a highly interdisciplinary science in many fields,such as design and synthesis of smart materials,drug delivery and molecular sensors.Supramolecular polymers constructed by noncovalent bonds,have attracted more and more attentions owing to their high strength and good stability,as well as the dynamic reversible properties.Pillararenes have been a new generation of host molecules due to their facile modification,highly symmetric structure and complexation with various guest molecules.However,most of the researches focused on the discrete pillararene monomers.Pillararene-containing polymers are rarely studied mainly due to the difficulties in synthesis of pillararene-containing polymers by conventional radical polymerization arising from the steric hindrance of pillararenes.This dissertation involved the synthesis of pillararene-containing polymers and the host-guest interactions in the supramolecular system.The main content was as follows:Pillar[5]arene derivative with a polymerizable group(DYP5A)was synthesized.Homopolymer pDYP5A,block polymer pDYP5A-b-pMPBPY and statistical copolymer p(DYP5A-co-MPBPY)were synthesized by metathesis cyclopolymerization(MCP)using the third Grubbs' catalyst(Ru-III).Then a pyridinium salt was synthesized and selected as the guest molecule(G)to form inclusion complexes with pillar[5]arene-containing polymers.By changing the molar ratios of the host and guest molecules,the ionic conductivities of the supramolecular system could be tuned.Meanwhile,it should be noted that the conductivities of polymers were in the sequence: pDYP5A?G > pDYP5A-b-pMPBPY?G > p-(DYP5A-co-MPBPY)?G,which suggested the regularity of polymers could affect the conductivity.Besides,the interactions between pillararene and guest molecule is indispensable to get high ionic conductivity,as demonstrated by the contrast experiments.Pillar[5]arene derivative with another polymerizable group(NMP5A)was synthesized.Homopolymer pNNMP5A,block polymer pNMP5A-b-pMPHMB and statistical copolymer p(NMP5A-co-MPHMB)were synthesized by ring-opening metathesis polymerization(ROMP)using the third Grubbs' catalyst(Ru-III).Then two pyridinium salts functionalized with polyethylene glycol or tetraphenylethylene were synthesized and selected as the guest molecules to form inclusion complexes with pillar[5]arene-containing polymers.The supramolecular brush polymers(SBPs)could self-assemble into micelles with aggregation-induced emission(AIE)property.The size and the fluorescence intensity of such micelles could be changed with different ratios of host and guest molecules in organic solvents.Meanwhile,butanedinitrile acting as a competitive guest,could destroy the structure of micelles,leading to the decreasing of the fluorescence intensity.