From Weakness To Strength: C-H/π-interactionguided Self-assembly And Gelation Of Poly (Benzyl Ether) Dendrimers

Dendrimers are a new class of macromolecules which possess tailor-made,highly branched and well-defined molecular structures.Its molecular size,shape,topology,number and properties of end groups can be designed and controlled precisely at the molecular level.Dendrimers are therefore receiving great interest as new building blocks in the self-assembling of supramolecular gel-phase materials.To date,a number of supramolecular organogels based on dendritic macromolecules have been reported.However,there have been very limited examples of dendritic organogels with diversities.In this dissertation,great efforts have been focused on the development of some new dendritic organogel systems and their self-assembly behaviors and potential applications.1.We have established a new series of dendritic gelators based on peripherally methyl-functionalized poly(benzyl ether)dendrimers,and proved that the weaker C-H/πinteractions are strong enough to induce supramolecular organogels.Their gelation property is highly dependent on the nature of the peripheral methyl groups.Single-crystal X-ray analysis and NMR spectroscopy revealed that the cooperative multiple C-H/π interactions is the key contributor in forming the self-assembled gels.This work illustrates the importance of weak C-H/π interactions in self-assembly process and provides new insights into the design of self-assembled nanomaterials.2.We have developed a new dendrimer based on peripherally methyl-functionalized poly(benzyl ether)dendrimers bearing a tetraphenyl ethylene unit at the core of dendrimer.It was found that this dendrimer was not effective for gelation in the solvents tested.The self-assembly behaviors in solution and the luminescence properties are waiting for further investigation.