Supramolecular Alternating Block Copolymers via Metal Coordination

• Published in: Chemistry : a European journal Vol. 15; no. 27; pp. 6605 - 6611
• Main Authors: Yang, Si Kyung, Ambade, Ashootosh V., Weck, Marcus
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag 06.07.2009; Wiley
• Subjects: Alkenes - chemistry; block copolymers; Chemistry; Chemistry, Multidisciplinary; Chemistry, Organic - methods; Magnetic Resonance Spectroscopy; metal coordination; Molecular Structure; Physical Sciences; polymerization; Polymers - chemical synthesis; Polymers - chemistry; ring‐opening metathesis; ruthenium; Ruthenium - chemistry; Science & Technology; supramolecular chemistry; block copolymers; polymerization; POLYMERS; OPENING METATHESIS POLYMERIZATION; TRANSFER RADICAL POLYMERIZATION; COMBINATION; MECHANICAL-PROPERTIES; ring-opening metathesis; FUNCTIONALIZATION; ruthenium; THERMODYNAMICS; PD; metal coordination; PINCER COMPLEXES; DYNAMICS; supramolecular chemistry
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200900573

Suprapolymers: The synthesis of symmetrically end‐functionalized polymers in a single step has been developed by means of ring‐opening metathesis polymerization by using a bimetallic ruthenium initiator and functional chain terminators. Self‐assembly of the resulting polymers allows for the formation of supramolecular alternating block copolymers (see figure). 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‐PdII 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. Suprapolymers: The synthesis of symmetrically end‐functionalized polymers in a single step has been developed by means of ring‐opening metathesis polymerization by using a bimetallic ruthenium initiator and functional chain terminators. Self‐assembly of the resulting polymers allows for the formation of supramolecular alternating block copolymers (see figure).