{
  "abstract": "Nonbenzenoid topologies offer a compelling strategy to tailor the electronic properties of low-dimensional carbon materials. Here, we report the on-surface synthesis of a nonalternant polymer incorporating a [7-5-5] cyclopenta[c,d]azulene (CPA) motif on Au(111) via thermally induced Ullmann coupling. Bond-resolved scanning tunneling microscopy confirms the robustness of the [7-5-5] framework. Scanning tunneling spectroscopy, together with dI/dV mapping supported by density functional theory calculations, reveals a remarkable narrow polymeric bandgap of 1.5 eV. The electronic structure is governed by the intramolecular charge transfer from the heptagonal ring to the adjacent fused pentagonal rings, resulting in a pronounced dipole moment despite being composed exclusively of carbon and hydrogen. Aromaticity analyses indicate the coexistence of locally aromatic and slightly antiaromatic regions, highlighting the intrinsic electronic frustration associated with the nonalternant topology. These findings demonstrate how the controlled incorporation of [7-5-5] motifs enables the rational bandgap engineering in carbon-based polymers and expands the scope of nonbenzenoid design in on-surface synthesis.",
  "abstract_shown": true,
  "affiliations": [
    "ESISNA Group, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Inés de la Cruz 3, Madrid28049, Spain.",
    "Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 112/10, Prague 6162 00, Czech Republic.",
    "Departamento de Química Orgánica, Universidad de Granada (UGR), Unidad de Excelencia de Química UEQ, C. U. Fuentenueva, Granada18071, Spain.",
    "Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Madrid28049, Spain."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 12,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "S Jiménez-Fernández"
    },
    {
      "affs": [
        1
      ],
      "name": "F Villalobos",
      "orcid": "0000-0001-5858-3833"
    },
    {
      "affs": [
        2
      ],
      "name": "V Kumar"
    },
    {
      "affs": [
        0
      ],
      "name": "J I Martínez",
      "orcid": "0000-0002-2086-8603"
    },
    {
      "affs": [
        3
      ],
      "name": "J I Mendieta-Moreno"
    },
    {
      "affs": [
        0
      ],
      "name": "P L de Andrés"
    },
    {
      "affs": [
        0
      ],
      "name": "E Tosi",
      "orcid": "0000-0003-4926-654X"
    },
    {
      "affs": [
        0
      ],
      "name": "J A Martín-Gago",
      "orcid": "0000-0003-2663-491X"
    },
    {
      "affs": [
        2
      ],
      "name": "J M Cuerva",
      "orcid": "0000-0001-6896-9617"
    },
    {
      "affs": [
        0
      ],
      "name": "I Palacio",
      "orcid": "0000-0002-3345-4848"
    },
    {
      "affs": [
        2
      ],
      "name": "A G Campaña",
      "orcid": "0000-0001-5483-5642"
    },
    {
      "affs": [
        0
      ],
      "name": "C Sánchez-Sánchez",
      "orcid": "0000-0001-8644-3766"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/14yamyt6qthwz.bib",
  "cited_by": 0,
  "doi": "10.1021/jacs.6c08825",
  "fulltext_url": "https://europepmc.org/articles/PMC13721034",
  "id": "14yamyt6qthwz",
  "issns": [
    "0002-7863",
    "1520-5126"
  ],
  "landing_url": "https://europepmc.org/article/MED/42954538",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Article"
    ],
    [
      "openalex",
      "2204|Surface Chemistry and Catalysis"
    ]
  ],
  "openalex": "W7154575633",
  "pdf_url": "https://europepmc.org/articles/PMC13721034?pdf=render",
  "pmcid": "PMC13721034",
  "pmid": "42954538",
  "published": "2026-10-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/14yamyt6qthwz.ris",
  "sources": [
    {
      "first_seen": "2026-11-01T00:20:44Z",
      "native_id": "MED:42954538",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42954538"
    },
    {
      "first_seen": "2026-11-03T12:21:47Z",
      "native_id": "PMC13721034",
      "source": "pmc",
      "url": "https://doi.org/10.1021/jacs.6c08825"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "journal-openalex:1605|Chemical Reaction Mechanisms",
      "subfield": "organic"
    }
  ],
  "title": "On-Surface Synthesis of a Low Bandgap Cyclopenta[c,d]azulene-Based Polymer.",
  "title_text": "On-Surface Synthesis of a Low Bandgap Cyclopenta[c,d]azulene-Based Polymer.",
  "type": "peer-reviewed",
  "updated_at": "2026-11-03T12:21:47Z",
  "url": "https://research.draconitic.com/paper/14yamyt6qthwz",
  "venue": "Journal of the American Chemical Society",
  "versions": []
}