{
  "abstract": "Bis-amido-bis-sulfonamido, [Fe{4-NO2C6H3-1,2-(NCOCMe2NSO2)2CR1R2}(OH2)]- [2; R1/R2 = H/H (2a), H/CH3 (2b), CH3/CH3 (2c)], are NewTAML (NT) iron(III) oxidation catalysts. Herein we identify and mechanistically characterize a ligand-centered, catalyst-lifetime-controlling site (CR1R2), termed a KillSwitch (KS), that enables balancing technical performance with potential safety constraints in NT/Oxidant process design. Under catalytic conditions, CR1R2 sites containing two or one hydrogen(s), (2a, 2b, respectively), undergo deprotonation to form electron-rich ylides that accelerate NT oxidative degradation. The 2a-c series defines a KS susceptibility gradient arising from differential C-H bond acidities controlling the ylide-forming deprotonation─2a, 2b, and 2c represent high-susceptibility-, intermediate-susceptibility-, and null-susceptibility KS states, respectively, thereby providing substantial catalyst functional lifetime control with 2a < 2b ≪ 2c. Kinetic analysis gives similar 2a-c rate constants for H2O2 activation (kI) and substrate oxidation (kII), while catalyst inactivation rate constants (ki) increase markedly and differentially with increasing pH for 2a and 2b, but remain pH-independent for 2c, which degrades more slowly through a separate pathway. Access to null-KS 2c─essential for testing the KS hypothesis─required a decade-long synthetic effort culminating in the quantitative methylation of deprotonated 2b. The KS is expected to be transferable to other NTs with oxidative reactivities distinct from 2a-c, enabling a new dimension in catalyst design that broadly decouples catalytic oxidative aggression from catalyst lifetime. The KS thus provides a practical, safe, and sustainable by design strategy for balancing technical performances against catalyst lifetimes, should shorter-lived NTs become desirable in response to discoveries of postrelease NT adverse environmental effects.",
  "abstract_shown": true,
  "affiliations": [
    "Institute of Green Science (IGS), Carnegie Mellon University, Pittsburgh, Pennsylvania15213, United States.",
    "Carnegie Mellon University, Pittsburgh, Pennsylvania15213, United States.",
    "Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Ciudad de México04510, Mexico.",
    "Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland21218, United States."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 11,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Debojyoti Chakraborty",
      "orcid": "0009-0007-0255-4727"
    },
    {
      "affs": [
        0
      ],
      "name": "Minerva G Schafer",
      "orcid": "0000-0002-0361-8581"
    },
    {
      "affs": [
        0
      ],
      "name": "Xiaowei Ma",
      "orcid": "0000-0001-6313-4944"
    },
    {
      "affs": [
        1
      ],
      "name": "Chris Birch"
    },
    {
      "affs": [
        2
      ],
      "name": "Carlos Felipe Mejía",
      "orcid": "0000-0002-5031-3705"
    },
    {
      "affs": [
        2
      ],
      "name": "Rubén A Toscano"
    },
    {
      "affs": [
        2
      ],
      "name": "Ronan Le Lagadec",
      "orcid": "0000-0002-5679-2081"
    },
    {
      "affs": [
        3
      ],
      "name": "Maxime A Siegler",
      "orcid": "0000-0003-4165-7810"
    },
    {
      "affs": [
        1
      ],
      "name": "Kevin Noonan",
      "orcid": "0000-0003-4061-7593"
    },
    {
      "affs": [
        0
      ],
      "name": "Alexander D Ryabov",
      "orcid": "0000-0002-5255-1395"
    },
    {
      "affs": [
        0
      ],
      "name": "Terrence J Collins",
      "orcid": "0000-0003-2611-9184"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/325yt2fvp1fr2.bib",
  "cited_by": 0,
  "doi": "10.1021/jacs.6c11419",
  "fulltext_url": "https://europepmc.org/articles/PMC13693390",
  "id": "325yt2fvp1fr2",
  "issns": [
    "0002-7863",
    "1520-5126"
  ],
  "landing_url": "https://europepmc.org/article/MED/42912295",
  "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": [
    [
      "openalex",
      "1604|Metal-Catalyzed Oxygenation Mechanisms"
    ]
  ],
  "openalex": "W7220850638",
  "pdf_url": "https://europepmc.org/articles/PMC13693390?pdf=render",
  "pmcid": "PMC13693390",
  "pmid": "42912295",
  "published": "2026-10-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/325yt2fvp1fr2.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:14Z",
      "native_id": "MED:42912295",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42912295"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1604|Metal-Catalyzed Oxygenation Mechanisms",
      "subfield": "inorganic"
    }
  ],
  "title": "A Programmable KillSwitch in NewTAML Catalysts Decouples Oxidative Reactivity from Catalyst Lifetime.",
  "title_text": "A Programmable KillSwitch in NewTAML Catalysts Decouples Oxidative Reactivity from Catalyst Lifetime.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:20:14Z",
  "url": "https://research.draconitic.com/paper/325yt2fvp1fr2",
  "venue": "Journal of the American Chemical Society",
  "versions": []
}