Synthesis of terpyridine-terminated amphiphilic block copolymers and their self-assembly into metallo-polymer nanovesicles

Polystyrene-b-polyethylene glycol (PS-b-PEG) amphiphilic block copolymers featuring a terminal tridentate N,N,N-ligand (terpyridine) were synthesized for the first time through an efficient route. In this approach, telechelic chain-end modified polystyrenes were produced via reversible addition-fragmentation chain-transfer (RAFT) polymerization by using terpyridine trithiocarbonate as the chain-transfer agent, after which the hydrophilic polyethylene glycol (PEG) block was incorporated into the hydrophobic polystyrene (PS) block in high yields via a thiol-ene process. Following metal-coordination with Mn ²⁺ , Fe ²⁺ , Ni ²⁺ , and Zn ²⁺ , the resulting metallo-polymers were self-assembled into spherical, vesicular nanostructures, as characterized by dynamic light scattering and transmission electron microscopy (TEM) imaging.