{
  "abstract": "Acyl-1,4-dihydropyridines are readily accessible radical precursors, but their poten al as photoini ators has remained largely unexplored.Here we show that these easily prepared compounds are dual-mode photoini ators that operate across the visible spectrum.Under blue light (405-475 nm), they act directly as Type I photoini ators: photoinduced fragmenta on releases acyl radicals that polymerise acrylate and methacrylate monomers.In trimethylolpropane triacrylate, DHP-2-NMe₂ and DHP-5-OMe show the highest Type I ac vity, with DHP-2-NMe₂ inducing gela on in only 6 s at a loading of 0.042 wt%.Under green light (525 nm), the DHPs serve as co-ini ators in photosensi sed Type II systems.With porphyrin-, BODIPY-and xanthene-based photosensi sers, rapid photopolymerisa on is observed; DHP-5-OMe is the most consistent co-ini ator, and PdOEP gives gela on mes of 2-14 s (median 3 s).Subs tuent-dependent reac vity observed in radical-trapping experiments supports a photoinduced electron-transfer pathway that, under op mised condi ons, delivers a Giese-type adduct in 92% yield under green light.Finally, combining DHP-1-H with I2BDP in a photopolymerisable glass increases the holographic diffrac on efficiency at 532 nm from 43% to 82% and the refrac ve-index modula on from 1.43 × 10⁻³ to 2.39 × 10⁻³.Single-step synthesis, strong visible-light absorp on and complete photobleaching make acyl-DHPs a prac cal pla orm for visible-light photopolymerisa on and holographic pa erning.",
  "abstract_shown": true,
  "affiliations": [
    "School of Chemical and Pharmaceutical Sciences, Technological University Dublin, City Campus, Dublin, Ireland, D07 ADY7",
    "Centre for Synthesis and Chemical Biology, School of Chemistry",
    "University College Dublin",
    "Centre for Industrial & Engineering Optics, School of Physics, Clinical and Optometric Sciences",
    "Technological University Dublin"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Metodej Dvoracek"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Pratik Avinash"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Karthikeyan Manoharan"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Arun Madathil"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Luke Adams"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Tatsiana Mikulchyk"
    },
    {
      "affs": [
        0
      ],
      "name": "Mikhail A. Filatov"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Bartosz Bieszczad",
      "orcid": "0000-0002-9503-0792"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/55n6t7yb4arjs.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15009749/v1",
  "fulltext_url": null,
  "id": "55n6t7yb4arjs",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009749/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",
      "1605|Photopolymerization techniques and applications"
    ]
  ],
  "openalex": "W7215034850",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15009749/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-01",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/55n6t7yb4arjs.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:21Z",
      "native_id": "10.26434/chemrxiv.15009749",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009749/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1605|Photopolymerization techniques and applications",
      "subfield": "organic"
    }
  ],
  "title": "Acyl-1,4-Dihydropyridines as Efficient Dual-Mode Photoinitiators for Radical Polymerisation under Blue and Green Light",
  "title_text": "Acyl-1,4-Dihydropyridines as Efficient Dual-Mode Photoinitiators for Radical Polymerisation under Blue and Green Light",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:21Z",
  "url": "https://research.draconitic.com/paper/55n6t7yb4arjs",
  "venue": "ChemRxiv",
  "versions": []
}