Combining Modular Ligation and Supramolecular Self-Assembly for the Construction of Star-Shaped Macromolecules

A well-defined random copolymer of styrene (S) and chloromethylstyrene (CMS) featuring lateral chlorine moieties with an alkyne terminal group is prepared (P(S-co-CMS), $\overline{M}_{\rm n}$ = 5500 Da, PDI = 1.13). The chloromethyl groups are converted into Hamilton wedge (HW) entities (P(S-co-HWS), $\overline{M}_{\rm n}$ = 6200 Da, PDI = 1.13). The P(S-co-HWS) polymer is subsequently ligated with tetrakis(4-azidophenyl)methane to give HW-functional star-shaped macromolecules (P(S-co-HWS))4, $\overline{M}_{\rm n}$ = 25 100 Da, PDI = 1.08). Supramolecular star-shaped copolymers are then prepared via self-assembly between the HW-functionalized four-arm star-shaped macromolecules (P(S-co-HW))4 and cyanuric acid (CA) end-functionalized PS (PSCA, $\overline{M}_{\rm n}$ = 3700 Da, PDI = 1.04), CA end-functionalized poly(methyl methacrylate) (PMMACA, $\overline{M}_{\rm n}$ = 8500 Da, PDI = 1.13) and CA end-functionalized polyethylene glycol (PEGCA, $\overline{M}_{\rm n}$ = 1700 Da, PDI = 1.05). The self-assembly is monitored by 1H NMR spectroscopy and light scattering analyses.