Supramolecular alternating block copolymers via metal coordination.

A bimetallic ruthenium olefin metathesis initiator was synthesized and used to polymerize functionalized norbornenes, affording polymers that are living at both polymer chain-ends. Using this bis-ruthenium initiator strategy and combining it with functional chain-terminators, highly-efficient syntheses of either SCS-Pd(II) pincer- or pyridine-functionalized symmetrical telechelic polymers were developed. The terminal functional group incorporation was confirmed by 1H NMR spectroscopy analyses. The telechelic polymers were self-assembled into block copolymers by means of metal coordination between corresponding terminal recognition units. The self-assembly process was monitored by 1H NMR spectroscopy revealing nearly quantitative functionalization. The resulting supramolecular block copolymers were further characterized by viscometry and dynamic light scattering.