Construction Of Chiral Supramolecular Polymers And Study Of Circularly Polarized Luminescence Properties

Supramolecular self-assembly systems driven by non-covalent interactions have always been a major research hotspot in the field of supramolecular chemistry.In the process of supramolecular self-assembly,monomer molecules form long-range ordered supramolecular polymers under the synergistic action of various non-covalent forces.At the same time,the chirality of monomer molecules induces the formation of chiral supramolecular polymers.Chiral supramolecular polymers can exhibit outstanding chiral optical properties by introducing π-conjugated structures with excellent photophysical properties,which can be used to construct circularly polarized luminescence systems based on supramolecular polymers.In the first part,we designed and synthesized two kinds of phosphorescent supramolecular monomer molecules with similar structure,and studied the effect of heavy atom substitution on circularly polarized luminescence properties of supramolecular polymer system.Both monomers have carbonyl benzene structure as phosphorescence emission unit,and the difference lies in whether bromine atoms are substituted on the emission unit.Driven by hydrogen bonds and π-π stacking,two monomers can assemble supramolecular polymers with long-term order in nonpolar solvents,and the assembly process follows the synergistic polymerization mechanism of "nucleation-chain growth".Through UV-Vis spectra and variable temperature circular dichroism spectra,we studied the differences of photophysical properties and self-assembly parameters of two supramolecular polymers in detail,and constructed two circularly polarized phosphorescence systems based on supramolecular polymers.In the second part,we designed and synthesized pyrene supramolecular monomer to study the co-assembly behavior of supramolecular and receptor molecules.Driven by hydrogen bonding and π-π stacking,monomer molecules can be assembled into long-range ordered supramolecular polymers in dodecane.It can be seen from UV and CD spectra that the assembly of monomer molecules can be divided into two stages,and both follow the synergistic polymerization mechanism.In addition,the assembly path of pyrene monomer molecules is complex,and the receptor molecule TCNB can be co-assembled with pyrene molecules in the first stage,showing the characteristics of charge transfer state,while TCNB cannot be inserted into the polymer in the other stage.We have constructed a supramolecular self-assembly system with assembly path adjustment.The complexity of assembly path endows supramolecular polymer with switchable circularly polarized luminescence characteristics.