{
  "abstract": "Cyclic block copolymers are a captivating class of macromolecules with the potential for advanced materials applications due to their distinctive self-assembly behavior. Ring expansion metathesis polymerization (REMP) is a promising method towards such high molar mass cyclic polymers, but uncontrolled intermolecular ring-transfer processes have precluded its extension to cyclic block copolymers synthesis. As a result, the synthesis of cyclic block copolymers remains exceedingly rare. In this work, we utilize newfound living characteristics of REMP with cyclic Ru-benzylidene initiator Pyr-CB6 to develop novel block copolymerization methodology. Using an operationally simple sequential monomer-addition strategy followed by thermally triggered intramolecular backbiting, we produce cyclic multiblock copolymers of low dispersity (<1.2) and high yields (up to 97%). Mechanistic analyses elucidate the delicate role that pyridine plays in the polymerization process. As a metathesis inhibitor, pyridine makes intermolecular ring-transfer prohibitively slow, but permits intramolecular backbiting when triggered. Overall, this study demonstrates the power of REMP with Pyr-CB6 as a vehicle towards a diverse future of cyclic block copolymer materials and applications.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Chemistry and Molecular Engineering & Science Institute",
    "University of Washington"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Lucy P Miller"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Matthew R Golder",
      "orcid": "0000-0001-5848-7366"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3ge5w4gm8xng8.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.10002042/v2",
  "fulltext_url": null,
  "id": "3ge5w4gm8xng8",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.10002042/v2",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1605|Advanced Polymer Synthesis and Characterization"
    ]
  ],
  "openalex": "W7216275884",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.10002042/v2",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-02",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/3ge5w4gm8xng8.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "10.26434/chemrxiv.10002042",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.10002042/v2"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1605|Advanced Polymer Synthesis and Characterization",
      "subfield": "organic"
    }
  ],
  "title": "Cyclic Block Copolymers via Ring Expansion Metathesis Polymerization",
  "title_text": "Cyclic Block Copolymers via Ring Expansion Metathesis Polymerization",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/3ge5w4gm8xng8",
  "venue": "ChemRxiv",
  "versions": []
}