Orthogonally Self-Assembled Multifunctional Block Copolymers

We report the synthesis of telechelic poly(norbornene) and poly(cyclooctene) homopolyrners by ring-opening metathesis polymerization (ROMP) and their subsequent functionalization and block copolymer formation based on noncovalent interactions. Whereas all the poly(norbornene)s contain either a metal complex or a hydrogen-bonding moiety along the polymer side-chains, together with a single hydrogen-bonding-based molecular recognition moiety at one terminal end of the polymer chain. These homopolymers allow for the formation of side-chain-functionalized AB and ABA block copolymers through self-assembly. The orthogonal natures of all side- and main-chain self-assembly events were demonstrated by H-1 NMR spectroscopy and isothermal titration calorimetry. The resulting fully functionalized block copolymers are the first copolymers combining both side- and main-chain self-assembly, thereby providing a high degree of control over copolymer functionalization and architecture and bringing synthetic materials one step closer to the dynamic self-assembly structures found in nature.