{
  "abstract": "Designing multifunctional polymers that combine thermal stability, selective optical response, and biological activity remains a key challenge in smart materials development. Herein, we report a novel pyridine-functionalized naphthoxazine monomer (Py-NZ) synthesized via a one-pot Mannich condensation and fully characterized by 1D/2D NMR, FTIR, and HRMS. DFT calculations confirmed the optimized geometry, showing excellent agreement with experimental data (RMSD = 0.018 Å; mean IR error = 0.43%), validating its extended π-conjugated structure. Thermogravimetric analysis of the cured Poly(Py-NZ) revealed outstanding thermal stability, with a char yield of 69% at 800 °C and a limiting oxygen index (LOI) of 45.1, indicating strong flame-retardant potential. UV-Vis and fluorescence spectroscopy demonstrated that metal coordination significantly modifies the optical behavior. Among the tested metal ions, Zn²⁺ induced a marked fluorescence enhancement due to its d¹⁰ configuration, which suppresses nonradiative decay and favors radiative emission. Py-NZ also exhibited strong acid-responsive fluorescence: high HCl concentrations quenched emission via protonation-induced nonradiative pathways, while lower acidity restored intensity, confirming its dual-responsive chemosensing capability for both metal ions and protons. Biological evaluation showed moderate antibacterial activity against Staphylococcus aureus and Escherichia coli, with the protonated form exhibiting enhanced activity against Gram-positive bacteria (MIC = 15.6 µg/mL). In DPPH antioxidant assays, all compounds displayed dose-dependent reductive activity comparable to ascorbic acid, with the Zn²⁺-coordinated complex showing the highest potency of nanomolarity radical scavenging affinities (IC₅₀ = 0.15 ± 0.01 vs. 0.041 ± 0.0062 for ascorbic acid). Overall, this work establishes a versatile platform for naphthoxazine-based multifunctional materials with potential applications in flame-retardant coatings, optical sensing, and biomedical fields.",
  "abstract_shown": true,
  "affiliations": [
    "Chemistry Department, Faculty of Education and Science, Albaydha University, Rada'a, Albaydha, Yemen. abdualsalam735@gmail.com.",
    "Department of Pharmacy, Faculty of Medicine and Health Sciences, Ar- Rasheed Smart University, Sana'a, Yemen. abdualsalam735@gmail.com.",
    "Chemistry Department, School of Science, The University of Jordan, Amman, 11942, Jordan. abdualsalam735@gmail.com.",
    "Chemistry Department, School of Science, The University of Jordan, Amman, 11942, Jordan.",
    "Department of Pharmaceutics and Pharmaceutical Technology, School of Pharmacy, The University of Jordan, Amman, 11942, Jordan.",
    "Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman, 11942, Jordan.",
    "Chemistry Department, School of Science, The University of Jordan, Amman, 11942, Jordan. maldamen@ju.edu.jo."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Abdulsalam Mahdy",
      "orcid": "0009-0009-2096-074X"
    },
    {
      "affs": [
        3
      ],
      "name": "Jalal A Zahra"
    },
    {
      "affs": [
        4
      ],
      "name": "Randa N Haddadin"
    },
    {
      "affs": [
        5
      ],
      "name": "Violet Kasabri"
    },
    {
      "affs": [
        6
      ],
      "name": "Murad A AlDamen"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7cq5jkc1ewpv1.bib",
  "cited_by": 0,
  "doi": "10.1186/s13065-026-01887-x",
  "fulltext_url": "https://europepmc.org/articles/PMC13689125",
  "id": "7cq5jkc1ewpv1",
  "issns": [
    "2661-801X"
  ],
  "landing_url": "https://europepmc.org/article/MED/42907927",
  "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": [
    [
      "lcc",
      "QD1-999"
    ],
    [
      "openalex",
      "2505|Luminescence and Fluorescent Materials"
    ]
  ],
  "openalex": "W7171315681",
  "pdf_url": "https://europepmc.org/articles/PMC13689125?pdf=render",
  "pmcid": "PMC13689125",
  "pmid": "42907927",
  "published": "2026-07-01",
  "publisher": "BMC",
  "ris": "https://research.draconitic.com/paper/7cq5jkc1ewpv1.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:57Z",
      "native_id": "MED:42907927",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42907927"
    },
    {
      "first_seen": "2026-10-30T13:45:35Z",
      "native_id": "7a0f3c3bafc549bab00c0113152692c8",
      "source": "doaj",
      "url": "https://doi.org/10.1186/s13065-026-01887-x"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2505|Luminescence and Fluorescent Materials",
      "subfield": "materials-polymers"
    }
  ],
  "title": "A novel pyridine-functionalized naphthoxazine: thermal stability, proton and metal ion-responsive optical sensing, and biological activity with DFT validation.",
  "title_text": "A novel pyridine-functionalized naphthoxazine: thermal stability, proton and metal ion-responsive optical sensing, and biological activity with DFT validation.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T13:45:35Z",
  "url": "https://research.draconitic.com/paper/7cq5jkc1ewpv1",
  "venue": "BMC chemistry",
  "versions": []
}