{
  "abstract": "Metal phthalocyanines (MPc) are a versatile molecular platform for applications ranging from organic optoelectronic devices to single-atom catalysis (SAC). Their adsorption and layer formation on the prototypical transparent electrode substrates of organic optoelectronic devices is directly relevant for charge injection and transport across the organic-oxide interface. Moreover, the well-defined M-N$_4$ coordination of the metal cation defines their activity as SACs for (electro-)catalysis. Here, the adsorption of the metal-free phthalocyanine (H$_2$Pc) is characterized on In$_2$O$_3$(111) using low-temperature STM, nc-AFM, and STS. In$_2$O$_3$ is not only a model system of indium tin oxide (ITO) but also an active catalytic material for CO$_2$ reduction. H$_2$Pc adsorbs in the same site and configuration reported for copper phthalocyanine [J. Mater. Chem. C 13, 17650-17661 (2025)] and for the majority of cobalt phthalocyanine [Surf. Sci. 722, 122065 (2022)]. Despite this shared preference in adsorption site, H$_2$Pc cannot be organized into extended and ordered monolayer structures by gentle annealing: the molecule starts to decompose at $\\approx$50$^\\circ$C, well below the temperature used to grow monolayers of CoPc and CuPc. Self-metalation is not observed on stoichiometric In$_2$O$_3$(111). On the reduced surface where In$^0$ adatoms are present, new H$_2$Pc-related features appear but cannot be identified by imaging only. The comparison of H$_2$Pc with CoPc and CuPc identifies distinct roles of the central metal ion in the metal-Pc/In$_2$O$_3$(111) systems: it acts as a structural anchor that stabilizes the macrocycle against decomposition on the surface, and it modifies the frontier-orbital character in ways that determine whether a second adsorption configuration is populated.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.08742",
  "author_total": 8,
  "authors": [
    {
      "name": "Viktoria Waidbacher"
    },
    {
      "name": "Sarah Tobisch"
    },
    {
      "name": "Faith J. Lewis"
    },
    {
      "name": "Moritz Eder"
    },
    {
      "name": "Michael Schmid"
    },
    {
      "name": "Gareth Parkinson"
    },
    {
      "name": "Ulrike Diebold"
    },
    {
      "name": "Margareta Wagner"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5ec9184ds9v7v.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.08742",
  "fulltext_url": null,
  "id": "5ec9184ds9v7v",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.08742",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ],
    [
      "openalex",
      "2204|Surface Chemistry and Catalysis"
    ]
  ],
  "openalex": "W7212021897",
  "pdf_url": "https://arxiv.org/pdf/2609.08742",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5ec9184ds9v7v.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:52Z",
      "native_id": "2609.08742",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.08742"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "The absence of a central metal ion destabilizes phthalocyanine on In$_2$O$_3$(111)",
  "title_text": "The absence of a central metal ion destabilizes phthalocyanine on In_2O_3(111)",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:52Z",
  "url": "https://research.draconitic.com/paper/5ec9184ds9v7v",
  "venue": "arXiv",
  "versions": []
}