{
  "abstract": "Herein, the anion effects on p K a values of organophosphonium salts in o -difluorobenzene are reported. Using the autoprotolysis constants of 2-(4-trifluoromethanesulfonato)phenylmalononitrile as an anchor, the p K a values of eight organophosphonium bistriflimides are experimentally determined in three polar fluorinated arenes via 31 P{ 1 H} NMR spectroscopic titration. Subsequently, the p K a values of eight corresponding organophosphonium tetrafluoroborates and eight corresponding organophosphonium tetraphenylborates soluble in o -difluorobenzene are further experimentally determined. These p K a values show significant differences due to different counter-anions. Further DFT calculations reveals that the anions BF 4 – and NTf 2 – in o-difluorobenzene form hydrogen-bonded contact ion pairs with organophosphonium cation, but BPh 4 – forms contact ion pairs via Coulombic interactions with it. In addition to providing important guidance for future improvement of DFT and AI for predicting p K a values and thermodynamic analyses in low dielectric constant solvents, this work also provides a more comprehensive understanding of anion effects in organic and inorganic X–H bond breaks and formations.",
  "abstract_shown": true,
  "affiliations": [
    "State Key Laboratory of Elemento-organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Weijin Road No. 94, Tianjin, China, 300071",
    "Haihe Laboratory of Sustainable Chemical Transformations",
    "Department of Chemistry",
    "Tsinghua University"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Yunfei Liang"
    },
    {
      "affs": [
        0
      ],
      "name": "Xiangmei Kong"
    },
    {
      "affs": [
        0
      ],
      "name": "Zhenbo Guo"
    },
    {
      "affs": [
        0
      ],
      "name": "Shanhui Zhu"
    },
    {
      "affs": [
        0
      ],
      "name": "Jun Chen"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Tianfei Liu",
      "orcid": "0000-0002-9961-0137"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Jin-Pei Cheng"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1kpesj8fhhz40.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008397/v1",
  "fulltext_url": null,
  "id": "1kpesj8fhhz40",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008397/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",
      "1605|Chemical Reaction Mechanisms"
    ]
  ],
  "openalex": "W7211886857",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008397/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-07",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/1kpesj8fhhz40.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:17Z",
      "native_id": "10.26434/chemrxiv.15008397",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008397/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1605|Chemical Reaction Mechanisms",
      "subfield": "organic"
    }
  ],
  "title": "Anion effects on pKa values of organophosphonium salts in o-difluorobenzene and implications",
  "title_text": "Anion effects on pKa values of organophosphonium salts in o-difluorobenzene and implications",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:17Z",
  "url": "https://research.draconitic.com/paper/1kpesj8fhhz40",
  "venue": "ChemRxiv",
  "versions": []
}