{
  "abstract": "Dinitrosyl iron complexes (DNICs) are prevalent NO-derived iron species; yet the factors that govern their formation at non-heme iron centers remain poorly understood. Here, we show that secondary-sphere hydrogen bonding interaction, together with steric accessibility of the Fe center enables quantitative formation of a {Fe(NO)2}9 (1-DNIC) complex through a previously unrecognized NO-driven redox pathway. Reaction of [Fe(DIG2dien)]2+ (DIG2dien = N-methyl-bis[2-(N,N′-diisopropylguanidino)ethyl]amine) with NO gas affords [Fe(DIG2dien)(NO)2]+ (1-DNIC) as the sole detectable iron-containing product. Spectroscopic and computational characterization by Mössbauer, EPR, SQUID, IR, X-ray absorption spectroscopy and DFT calculation establish an S = 1/2 ground state and a hydrogen-bond-supported {Fe(NO)2}9 unit. Mechanistic studies support a self-sustaining pathway in which NO functions as both a nitrosylating agent and a reductant, thereby circumventing the stoichiometric constraints of the previously reported disproportionation mechanisms. Notably, the sterically hindered analogue [Fe(DIG3tren)]2+ (2, DIG3tren = tris(N’,N”-diisopropylguanidinyl-2-ethyl)amine) reacts with NO gas to form the linear, hydrogen-bonded {FeNO}7 complex [Fe(DIG3tren)(NO)]2+ (2-NO) rather than a DNIC. Furthermore, 1-DNIC transfers NO to the ferrous precursor 2, generating 2-NO with concomitant formation of trace N2O. These findings establish secondary-sphere hydrogen bonding as a key determinant of DNIC assembly and reveal a hydrogen-bond-mediated, NO-driven mechanism for quantitative DNIC formation at a non-heme iron center.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "name": "Matthias Jux"
    },
    {
      "name": "Maximilian Schütze"
    },
    {
      "name": "Munir Mardini"
    },
    {
      "name": "Konstantin Krause"
    },
    {
      "name": "Michael Haumann"
    },
    {
      "name": "Yong Wang"
    },
    {
      "name": "Kallol Ray",
      "orcid": "0000-0003-2074-8844"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0dw63jy9qtvtn.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008233/v1",
  "fulltext_url": null,
  "id": "0dw63jy9qtvtn",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008233/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",
      "1604|Metal-Catalyzed Oxygenation Mechanisms"
    ]
  ],
  "openalex": "W7207629456",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008233/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-03",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/0dw63jy9qtvtn.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:17Z",
      "native_id": "10.26434/chemrxiv.15008233",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008233/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1604|Metal-Catalyzed Oxygenation Mechanisms",
      "subfield": "inorganic"
    }
  ],
  "title": "Uncovering a Hydrogen-Bond-Enabled Pathway to Dinitrosyl Iron Complexes",
  "title_text": "Uncovering a Hydrogen-Bond-Enabled Pathway to Dinitrosyl Iron Complexes",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:17Z",
  "url": "https://research.draconitic.com/paper/0dw63jy9qtvtn",
  "venue": "ChemRxiv",
  "versions": []
}