{
  "abstract": "Phenolate (PhO-) is a prototypical chromophore and a recurring motif in photoactive biomolecular systems. Here, we use extreme-ultraviolet time-resolved photoelectron spectroscopy (XUV-TRPES) to probe how para-substitution redirects the photophysics of aqueous 4-nitrophenolate (4NP-) and 4-chlorophenolate (4CP-) anions. In 4NP-, following 400 nm excitation, internal charge reorganization accompanied by nitrogroup torsion forms a stabilized twisted intramolecular charge-transfer (TICT) configuration in 74 fs, efficiently funneling the population through a conical intersection to the ground state within 200 fs. Similar dynamics are seen upon excitation at 240 nm, although the initially excited state is even shorter-lived (40 fs). No hydrated electron production is seen at either wavelength. In 4CP-, following 240 nm excitation of the S2 state, internal conversion to S1 occurs within 120 fs. Chlorine substitution introduces a competing 1πσ* dissociative channel whose potential energy surface intersects S1, but the higher S1/1πσ* crossing barrier relative to 4BP- allows the S1 population to survive long enough (25 ps) for solvent-assisted electron ejection and internal conversion. The dynamics thus resemble those of PhO- rather than the sub-picosecond dissociative relaxation of 4BP-. Taken together with our previous PhO- and 4-bromophenolate (4BP-) measurements, these results reveal how para-substitution across this prototypical series drives the accessibility of competing excited-state dynamical processes, leading to very different photostability and photochemistry.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Chemistry",
    "California",
    "Sungkyunkwan University",
    "Chemical Science Division",
    "Lawrence Berkeley National Laboratory"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Jaydeep Basu"
    },
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Do Hyung Kang"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Neal Haldar"
    },
    {
      "affs": [
        0,
        1,
        3,
        4
      ],
      "name": "Daniel M Neumark"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/enwyadaxkq4w3.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010331/v1",
  "fulltext_url": null,
  "id": "enwyadaxkq4w3",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010331/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",
      "1606|Photochemistry and Electron Transfer Studies"
    ]
  ],
  "openalex": "W7221697970",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010331/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-13",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/enwyadaxkq4w3.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:24Z",
      "native_id": "10.26434/chemrxiv.15010331",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010331/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1606|Photochemistry and Electron Transfer Studies",
      "subfield": "physical"
    }
  ],
  "title": "Substituent Effects on the Photochemistry of Aqueous Phenolate-Based Anions Revealed by Extreme Ultraviolet Time-Resolved Photoelectron Spectroscopy",
  "title_text": "Substituent Effects on the Photochemistry of Aqueous Phenolate-Based Anions Revealed by Extreme Ultraviolet Time-Resolved Photoelectron Spectroscopy",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:24Z",
  "url": "https://research.draconitic.com/paper/enwyadaxkq4w3",
  "venue": "ChemRxiv",
  "versions": []
}