{
  "abstract": "Conformational changes in a chromophore can strongly influence its fluorescence properties. Here, we report the development of thioxanthone-based fluorescent sensors designed to suppress the characteristic butterfly-like deformation of the thioxanthone core upon metal-ion binding. To access the required 1,8-disubstituted scaffolds, we developed an efficient aryne-based synthesis of multisubstituted thioxanthones from readily available o -iodoaryl triflates and N , N , N’ , N’- tetramethylthiourea. Subsequent functionalization provided a series of thioxanthones bearing metal-coordinating substituents at the 1,8-positions. Evaluation of the resulting compounds identified a probe exhibiting pronounced and spectrally distinct fluorescence responses to Zn 2+ and Ca 2+ with high ON/OFF ratios, enabling clear discrimination between the two metal ions. Time-dependent DFT (TD-DFT) calculations for a simplified Zn 2+ complex indicated that coordination stabilizes a nearly planar thioxanthone structure and enhances the oscillator strength of the emissive transition. These results demonstrate the utility of controlling the butterfly-like deformation of the thioxanthone core for metal-ion-responsive fluorescence sensing.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "name": "Riku Arakaki"
    },
    {
      "name": "Mayu Kawada"
    },
    {
      "name": "Suguru Yoshida",
      "orcid": "0000-0001-5888-9330"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1428xn1vf5zfj.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010518/v1",
  "fulltext_url": null,
  "id": "1428xn1vf5zfj",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010518/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",
      "1607|Molecular Sensors and Ion Detection"
    ]
  ],
  "openalex": "W7221981836",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010518/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-15",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/1428xn1vf5zfj.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:24Z",
      "native_id": "10.26434/chemrxiv.15010518",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010518/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1607|Molecular Sensors and Ion Detection",
      "subfield": "physical"
    }
  ],
  "title": "Aryne-Enabled Synthesis of 1,8-Disubstituted Thioxanthones for Conformationally Gated Metal-Ion Sensing",
  "title_text": "Aryne-Enabled Synthesis of 1,8-Disubstituted Thioxanthones for Conformationally Gated Metal-Ion Sensing",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:24Z",
  "url": "https://research.draconitic.com/paper/1428xn1vf5zfj",
  "venue": "ChemRxiv",
  "versions": []
}