{
  "abstract": "Despite their considerable technological potential, structure-property relationships in intramolecular charge-transfer-based photoswitches remain poorly established. Here, we present a quantum-chemical investigation of the first hyperpolarizability (β) of a family of dithienylethene (DTE)-based photoswitches, considering static, electro-optic Pockels, and second-harmonic-generation (SHG) responses. Eight donor (D)/acceptor (A) architectures, with and without alkyne (y) π-extension, are investigated in their open- and closed-ring forms using density functional theory [CAM-B3LYP/6-31+G(d,p)/GD3BJ/(PCM)] in the gas phase and three continuum solvents, with dynamic responses evaluated at 1064 nm. Ring closure generally enhances total first hyperpolarizability (βtot) by restoring through core conjugation, while donor-acceptor asymmetry emerges as the dominant structural factor governing large NLO responses. Alkyne extension further enhances the response when coupled with a push-pull architecture. Solvation modulates both the magnitude and direction of the response, producing pronounced amplification of the closed/open βtot ratio in selected systems and a striking reorientation of the SHG response vector for Dy-yAopen. Time-dependent DFT analysis suggests that the reorientation is associated with a redistribution among nearby excited-state contribution. Importantly, βtot and the directional alignment ratio η are not necessarily correlated. We therefore introduce RNLO as a combined comparative descriptor that captures both response magnitude and directionality. RNLO identifies the closed push-pull architectures, particularly Dy-yAclosed, D-yAclosed, and Dy-Aclosed, as the most favorable systems among the considered chromophores. Overall, the results show that NLO performance is governed by the coupled effects of donor-acceptor asymmetry, ring closure, π-extension, and dielectric environment, and that optimization of both response magnitude and directionality is essential for establishing meaningful structure-property relationships in DTE photoswitches.",
  "abstract_shown": true,
  "affiliations": [
    "Institut für Theoretische Chemie, Universität Ulm Oberberghof 7 89081 Ulm Germany.",
    "Institut für Biologie, Humboldt-Universität zu Berlin Invalidenstraße 42 10115 Berlin Germany ramprasad.misra@hu-berlin.de.",
    "Department of Chemistry, GITAM School of Science Hyderabad 502329 Telangana India rudra.smgr@gmail.com rsarkar2@gitam.edu."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Kanchan Sarkar",
      "orcid": "0000-0002-0025-7055"
    },
    {
      "affs": [
        1
      ],
      "name": "Ramprasad Misra",
      "orcid": "0000-0002-1599-404X"
    },
    {
      "affs": [
        0
      ],
      "name": "Axel Groß",
      "orcid": "0000-0003-4037-7331"
    },
    {
      "affs": [
        2
      ],
      "name": "Rudraditya Sarkar",
      "orcid": "0000-0001-7915-8625"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dbbr4j92ve6d8.bib",
  "cited_by": 0,
  "doi": "10.1039/d6ra08114b",
  "fulltext_url": "https://europepmc.org/articles/PMC13715864",
  "id": "dbbr4j92ve6d8",
  "issns": [
    "2046-2069"
  ],
  "landing_url": "https://europepmc.org/article/MED/42953487",
  "language": "eng",
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Chemistry"
    ],
    [
      "openalex",
      "2504|Nonlinear Optical Materials Research"
    ]
  ],
  "openalex": "W7224086061",
  "pdf_url": "https://europepmc.org/articles/PMC13715864?pdf=render",
  "pmcid": "PMC13715864",
  "pmid": "42953487",
  "published": "2026-10-28",
  "publisher": "Royal Society of Chemistry",
  "ris": "https://research.draconitic.com/paper/dbbr4j92ve6d8.ris",
  "sources": [
    {
      "first_seen": "2026-10-31T00:20:40Z",
      "native_id": "MED:42953487",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42953487"
    },
    {
      "first_seen": "2026-11-01T12:23:03Z",
      "native_id": "PMC13715864",
      "source": "pmc",
      "url": "https://doi.org/10.1039/d6ra08114b"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2504|Nonlinear Optical Materials Research",
      "subfield": "materials-polymers"
    }
  ],
  "title": "First hyperpolarizability of dithienylethene-based photoswitches: a structure-property relationship study.",
  "title_text": "First hyperpolarizability of dithienylethene-based photoswitches: a structure-property relationship study.",
  "type": "peer-reviewed",
  "updated_at": "2026-11-01T12:23:03Z",
  "url": "https://research.draconitic.com/paper/dbbr4j92ve6d8",
  "venue": "RSC advances",
  "versions": []
}