{
  "abstract": "The synthesis routes, crystal and molecular structures, and controlled thermal decomposition reactions of two [pentamminecobalt(iii) compounds having a coordinated chromate ion, [Co(NH₃)₅CrO₄]Cl (compound 1) and [Co(NH₃)₅CrO₄]₂CrO₄ (compound 2) were studied experimentally. Quantum chemical optimizations and QTAIM calculations were performed for compounds 1 and 2, and the selected Bond Critical Points (BCPs) properties were discussed. The extended hydrogen-bond network between the coordinated chromate ions and ammonia ligands acts as reactive redox reaction centres, and both compounds show solid-phase quasi-intramolecular redox reactions with the formation of Co[Co0.5Cr1.5O3.75] and Co[Co0.2Cr1.8O3.90] nanosized regular spinels with nominal Co : Cr = 1 : 1 and 2 : 3 molar ratios, respectively. The tetrahedral positions of these spinels are filled with CoII ions. The octahedral positions of 2 : 3 and 1 : 1 spinels prepared in air are filled CrIII and mainly with CoIII ions. The 2 : 3 spinel prepared under N₂ shows a similar distribution of ions, whereas the 1 : 1 spinel prepared under N₂ contains only CoII ions at T-4, and CrIII, CoIII, and CoII ions at the OC-6 positions, resulting in a strongly defective structure. The position of the chromate ions (inner-sphere coordinated or outer-sphere non-coordinated) plays an important role in the quasi-intramolecular redox reactions and thermal decomposition characteristics of compounds 1 and 2. The inner-sphere coordinated chromate ions of both compounds took part in redox reactions with their own coordinated ammonia only after the loss of the fifth ammonia, in an endothermic ligand-releasing and an exothermic redox reaction mediated by the outer-sphere chromate ion for compounds 1 and 2, respectively. The cobalt(iii) content of both complexes is also reduced completely to cobalt(ii). These spinels were proven to be active catalysts in the visible-light-driven photocatalytic oxidation of rhodamine B with H₂O₂.",
  "abstract_shown": true,
  "affiliations": [
    "Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences Budapest Hungary tulik.balint@ttk.hu beres.kende.attila@ttk.hu bereczki.laura@ttk.hu trif.laszlo@ttk.hu karoly.zoltan@ttk.hu kotai.laszlo@ttk.hu.",
    "Department of Physical Chemistry and Materials Science, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics Budapest Hungary.",
    "Laboratory of Structural Chemistry and Biology, Institute of Chemistry, ELTE Eötvös Loránd University Budapest Hungary zsolt.durvanger@ttk.elte.hu.",
    "HUN-REN-ELTE Protein Modelling Research Group Budapest Hungary.",
    "Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University 1-1 Minami-Osawa, Hachi-Oji Tokyo 192-0397 Japan kubuki@tmu.ac.jp.",
    "Department of Organic Chemistry and Technology, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics Budapest Hungary farkas.attila@vbk.bme.hu.",
    "Division of Materials Chemistry, Ruđer Bošković Institute Zagreb Croatia Stjepko.Krehula@irb.hr.",
    "Institute of Chemistry, Faculty of Natural Sciences and Mathematics, Ss. Cyril and Methodius University Skopje Republic of North Macedonia vladimirpetrusevski@yahoo.com.",
    "Institute of Chemistry, ELTE Eötvös Loránd University Budapest Hungary homonnay.zoltan@ttk.elte.hu.",
    "Faculty of Physical Chemistry, University of Belgrade Belgrade Serbia milica@bio.bg.ac.rs saska@ffh.bg.ac.rs dusan.dimic@ffh.bg.ac.rs."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 15,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Bálint Tulik",
      "orcid": "0009-0009-9951-2121"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Zsolt Dürvanger",
      "orcid": "0000-0002-2652-4916"
    },
    {
      "affs": [
        4
      ],
      "name": "Shiro Kubuki",
      "orcid": "0000-0001-8255-7811"
    },
    {
      "affs": [
        5
      ],
      "name": "Attila Farkas"
    },
    {
      "affs": [
        6
      ],
      "name": "Stjepko Krehula",
      "orcid": "0000-0001-6956-4478"
    },
    {
      "affs": [
        7
      ],
      "name": "Vladimir M Petruševski"
    },
    {
      "affs": [
        0
      ],
      "name": "Laura Bereczki"
    },
    {
      "affs": [
        8
      ],
      "name": "Zoltán Homonnay"
    },
    {
      "affs": [
        9
      ],
      "name": "Milica Marković"
    },
    {
      "affs": [
        9
      ],
      "name": "Aleksandra Rakic",
      "orcid": "0000-0003-1489-6373"
    },
    {
      "affs": [
        9
      ],
      "name": "Dušan Dimić"
    },
    {
      "affs": [
        0
      ],
      "name": "László Trif"
    },
    {
      "affs": [
        0
      ],
      "name": "Zoltán Károly"
    },
    {
      "affs": [
        0
      ],
      "name": "László Kótai",
      "orcid": "0000-0001-6375-3120"
    },
    {
      "affs": [
        0
      ],
      "name": "Kende Attila Béres",
      "orcid": "0000-0003-4257-0581"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/da8nt0h1w2g5r.bib",
  "cited_by": 0,
  "doi": "10.1039/d6ra06540f",
  "fulltext_url": "https://europepmc.org/articles/PMC13693807",
  "id": "da8nt0h1w2g5r",
  "issns": [
    "2046-2069"
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  "landing_url": "https://europepmc.org/article/MED/42921270",
  "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": [
    [
      "heading",
      "Chemistry"
    ],
    [
      "openalex",
      "1605|Inorganic and Organometallic Chemistry"
    ]
  ],
  "openalex": "W7223335945",
  "pdf_url": "https://europepmc.org/articles/PMC13693807?pdf=render",
  "pmcid": "PMC13693807",
  "pmid": "42921270",
  "published": "2026-10-23",
  "publisher": "Royal Society of Chemistry",
  "ris": "https://research.draconitic.com/paper/da8nt0h1w2g5r.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:33Z",
      "native_id": "MED:42921270",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42921270"
    },
    {
      "first_seen": "2026-11-07T12:23:48Z",
      "native_id": "PMC13693807",
      "source": "pmc",
      "url": "https://doi.org/10.1039/d6ra06540f"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1605|Inorganic and Organometallic Chemistry",
      "subfield": "organic"
    }
  ],
  "title": "The reactivity of coordinated and uncoordinated chromate ions in the quasi-intramolecular redox reactions of [pentaamminechromatocobalt(iii)] chloride and chromate resulting in tuneable cobalt-chromium spinel oxide catalysts.",
  "title_text": "The reactivity of coordinated and uncoordinated chromate ions in the quasi-intramolecular redox reactions of [pentaamminechromatocobalt(iii)] chloride and chromate resulting in tuneable cobalt-chromium spinel oxide catalysts.",
  "type": "peer-reviewed",
  "updated_at": "2026-11-08T12:21:08Z",
  "url": "https://research.draconitic.com/paper/da8nt0h1w2g5r",
  "venue": "RSC advances",
  "versions": []
}