{
  "abstract": "A single, synthetically controllable structural coordinate capable of simultaneously enhancing charge-transfer (CT) character and spin-orbit coupling (SOC) is highly sought after in purely organic chromophore design, yet has not been demonstrated. We show that excited-state planarization (ESP) in an anthracene-anthraquinone donor-acceptor emitter is exactly such a coordinate, governing one electronic variable, the CT weight of the emissive singlet, that simultaneously sets SOC into an acceptor-localized triplet channel in a near-linear, quantified relationship (R2 = 0.997), and we propose this as a general, transferable design principle for donor-acceptor chromophores. The resulting CT character exhibits a Solvatochromic response that exceeds current literature values for a neutral, purely organic, small-molecule donor-acceptor chromophore, with a slope of 25,384 cm-1 per unit Δf and R2 = 0.928 across a nine-solvent panel, which is the best yet reported. Finally, the compound exhibits genuine room-temperature phosphorescence (RTP) despite an anomalously small experimental singlet-triplet gap (0.08 eV), with emission confirmed, computationally and experimentally, to originate from the second triplet state rather than the lowest, a definitive instance of anti-Kasha phosphorescence; we provide a plausible, computationally supported mechanism for this behavior, in which reverse intersystem crossing (RISC) suppression is the most plausible explanation.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "name": "Ajeet K. Singh",
      "orcid": "0009-0001-1783-1586"
    },
    {
      "name": "Nancy Punia"
    },
    {
      "name": "Ayushi Tiwari"
    },
    {
      "name": "Swapnil Ganguly"
    },
    {
      "name": "Inamur Rahaman Laskar"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/69cx15dv41b9a.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010011/v1",
  "fulltext_url": null,
  "id": "69cx15dv41b9a",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010011/v1",
  "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",
      "2505|Luminescence and Fluorescent Materials"
    ]
  ],
  "openalex": "W7220848879",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010011/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-06",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/69cx15dv41b9a.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "10.26434/chemrxiv.15010011",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010011/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2505|Luminescence and Fluorescent Materials",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Excited-State Planarization Couples Charge-Transfer Character and Spin-Orbit Coupling to Enable High Efficiency Solvatochromism in an Anti-Kasha Donor-Acceptor Phosphor",
  "title_text": "Excited-State Planarization Couples Charge-Transfer Character and Spin-Orbit Coupling to Enable High Efficiency Solvatochromism in an Anti-Kasha Donor-Acceptor Phosphor",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/69cx15dv41b9a",
  "venue": "ChemRxiv",
  "versions": []
}