A 99Tc NMR chemical shift database: an accounting of reported 99Tc NMR chemical shifts

The primary dataset contains a comprehensive collection of reported 99Tc NMR chemical shifts. A second dataset encodes the literature records cross-referenced in the primary database. The project is on-going and further chemical shift records will be added in continuous versions as accidental omissions are identified and further work on 99Tc NMR is performed. 

Identified omissions and errors can be communicated directly to MRJ by e-mail (maximilian.roca-jungfer@partner.kit.edu) for fixing in future iterations. 

A publication describing the database and the interface for its use is planned in the near future - users are requested to cite at least the general ZENODO DOI and the corresponding journal publication once available for appropriate crediting according to the licence information; if a specific time-stamped version of the database was used, please also cite the version-specific DOI according to FAIR principle standards. 

An .html-based user interface (NMR_Database_IFRAME.html) for direct non-expert access to the database is provided as implemented on the website of the creator (rocajungfer.de) and features filtering options (the GUI and filter engine is encoded in nmr_subpanel.html that is loaded through the IFRAME file), e.g., for oxidation states or labeled compound sub-sets as well as search algorithms for different other attributes such as publications. Load the NMR_Database_IFRAME file in a browser to access an interactive GUI (not that database.js and database_refs.js as well as NMR_subpanel need to be in the same folder as the IFRAME file). Note that not every change to either the GUI, filtering functions or the database results in a newly updated version with a unique DOI on ZENODO.

The most recent database state and GUI version is currently hosted and functionally searchable at https://rocajungfer.de/Research_TcNMR.html . 

You can submit your 99Tc NMR data for inclusion in the database by providing structured information in .js format directly to MRJ:

 {
    compound_id: "TC-000XXX",
    status: "public",
    formula: "",
    aliases: [],
    formal_ox_state: ,
    structural_subsets: ["", ""],
    smiles: "N/A",
    experimental_records: [
      {
        record_id: "TC-000XXX-NMR-000001",
        status: "public",
        chemical_shift: ,
        line_width_v12: ,
        solvent: "",
        multiplicity: "",
        coupling: "",
        J: ,
        experimental_details: "",
        pub_ref: "REF-000XXX",
        comment: ""
      },
      {
        record_id: "TC-000XXX-NMR-000002",
        status: "public",
        chemical_shift: ,
        line_width_v12: ,
        solvent: "",
        multiplicity: "",
        coupling: "",
        J: ,
        experimental_details: "",
        pub_ref: "REF-000XXX",
        comment: ""
      },

explanation of data items:

compound_id: ID will be assigned during curation and does not need to be provided (keep the template entry)

formula: chemically reasonable formula - special ligands or common names can be defined under "aliases"

aliases: alternative names and ligand definitions

smiles: SMILES-type description of structure or substructures (ligands) can be given

formal_ox_state: numeric formal oxidation state value

structural_subsets: existing subset nomenclature; the following subsets are already defined: "(CNR)2", "(CNR)4", "(CNR)5", "(CNR)6", "(CO)2", "(CO)4", "(CO)5", "Arene", "Br-", "Carbene", "Carboxylate", "cis-(O)2", "Cl-", "Cluster", "CN-", "CNR", "CO", "Cp", "CpR", "Diazenido", "Dimer", "F-", "fac-(CNR)3", "fac-(CO)2(NO)", "fac-(CO)3", "fac-(O)3", "H", "H2O", "I-", "Macrocycle", "mer-(CNR)3", "mer-(CO)3", "Monooxido", "N,N-chelate", "N,O-chelate", "N,Se-chelate", "N,Te-chelate", "NH3", "Nitrido", "NO", "(NO)(CpR)(PR3)", "NS", "O,O-chelate", "O,S-chelate", "OH-", "Organyl", "Others", "P,P-chelate", "Peroxido", "Pincer", "Polyol", "PR3", "S,S-chelate", "Solvento", "TcO4-", "Tetramer", "trans-(O)2", "Trimer", "Tripod", "Unidentified"

record_id: ID will be assigned during curation and does not need to be provided (keep the template entry)

chemical_shift: numerical chemical shift value referenced to TcO4- 

line_width_v12: numerical value of full width at half maximum for the resonance

solvent: indicate the solvent used or for solids give matrix/pure solid

multiplicity: standard descriptors "s", "d", "t", ...

coupling: identify coupling nuclei acccording to nomenclature: nJ(99Tc,X)

J: numeric coupling constant value

experimental_details: measurement related information can be added (e.g., spectrometer frequency/magnet strength, pulse information, temperature, ...)

pub_ref: ID will be assigned during curation and does not need to be provided (keep the template entry)

comment: space for miscelaneous, additional, noteworthy comments, e.g., ambiguity or discrepancies with other literature

Bibliographic information can be supplied in this format:

  {
    reference_id: "REF-000XXX",
    year: "",
    title: "",
    authors: ["", ""],
    journal: "",
    volume: "",
    issue: "",
    page_equivalent: "",
    DOI: ""
  },

AI-usage disclosure:
Data integrity, labeling and extraction was cross-checked and validated using GPT-6 [OpenAI. (2026). ChatGPT (Version GPT-6 Sol) [Large language model]. https://chatgpt.com (Zugriff am 9. Oktober 2026).] after manual extraction, labeling and presorting. Transformation of manually preassembled data into a database format was performed using GPT-6. Although every step was audited by the author carefully and manually, mistakes/artifacts from either manual extraction or translation and automated check-paths cannot be excluded. Therefore, user feedback is appreciated and will be implemented upon reasonable request depending on the available author ressources. The .html GUI and search filter engines were programmed by the author with the help of the freely available Gemini model [Google. (2026). Gemini [Large language model]. https://gemini.google.com] and refined using GPT-6).