Substituent and State-Specific Solvent Influences on Novel NIR-Emitting ESIPT-Active Push–Pull Fluorescent Dyes Exhibiting Large Stokes Shifts

Substituent and State-Specific Solvent Influences on Novel NIR-Emitting ESIPT-Active Push–Pull Fluorescent Dyes Exhibiting Large Stokes Shifts | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Substituent and State-Specific Solvent Influences on Novel NIR-Emitting ESIPT-Active Push–Pull Fluorescent Dyes Exhibiting Large Stokes Shifts Negar Noroozi, Hossein Roohi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7446877/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 07 Mar, 2026 Read the published version in Chemical Papers → Version 1 posted 5 You are reading this latest preprint version Abstract The most attractive features of the ESIPT-cyanine dyes are their potential in molecular imaging, due to their unique photophysical properties, excellent biocompatibility, and high cell penetration ability. This study utilizes the TD-CAM-B3LYP quantum chemical method to investigate the photophysical properties of a series of near-infrared emitting dyes. These dyes are constructed around a central phenol ring that is functionalized with a strongly electron-withdrawing cyanine group (–CH = CH–R₂⁺) located ortho to the hydroxyl function, and feature tunable substituents (R₁) at the para position. The S₀ → S 1 absorption wavelengths for L1–L4 range approximately from 323 nm ( L1 ) to 527 nm ( L4 ) in water and from 329 nm (L1) to 520 nm ( L4 ) in DCM. Similarly, the emission wavelengths corresponding to the S₁–E (S₁–K) forms range from ~ 406 (~ 465) nm for L1 up to ~ 865 (~ 781) nm for L4 in water and 407 (468) nm to 809 (769) nm in DCM. The calculated Stokes shifts at S 1 -K state for L1-L4 in water and DCM are 141.0 and 138.1 nm for L1 , 297.3 and 257.8 nm for L2 , 249.2 and 243.4 nm for L3 , and 254.6 and 249.1 nm for L4 , respectively. Aligned with recent advances in ESIPT–cyanine dyes for fluorescence imaging, particularly in targeting acidic organelles such as lysosomes, the push–pull electron L2–L4 systems specifically L4 characterized by their large Stokes shifts that reduce self-reabsorption for high-contrast imaging, are anticipated to offer comparable benefits. ESIPT NIR dyes Cyanine Stokes shift TD-DFT Full Text Supplementary Files Suppdata.docx Cite Share Download PDF Status: Published Journal Publication published 07 Mar, 2026 Read the published version in Chemical Papers → Version 1 posted Reviewers agreed at journal 16 Sep, 2025 Reviewers invited by journal 06 Sep, 2025 Editor invited by journal 28 Aug, 2025 Editor assigned by journal 26 Aug, 2025 First submitted to journal 24 Aug, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7446877","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":511106766,"identity":"b230710f-c251-4d1c-abaa-335687f8dc03","order_by":0,"name":"Negar Noroozi","email":"","orcid":"","institution":"University of Guilan","correspondingAuthor":false,"prefix":"","firstName":"Negar","middleName":"","lastName":"Noroozi","suffix":""},{"id":511106767,"identity":"f35f6830-6df2-4f04-9bd7-d1abc6a9591d","order_by":1,"name":"Hossein Roohi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAzElEQVRIiWNgGAWjYBACAyBmZjCwAZLMDRAhZuK0pAFJRpK0MBwGUjAthIC59OGDjwsKztttOM7Y+LmAwU6egZ33AV4tln1pycYzDG4nbzjM2Cw9gyHZsIGZ3QC/w87wmEnzALUYHGZskOZhYE5gYGYj4BeIlnMgLc2/eRjqidZywA6opQ1oy2FitLAlG/MYJCdIArVY8xgcN2wjrIX54GOeP3b2fOcPH77NU1Etz89/DL8WGEhsgJjAwEDADgSwJ1bhKBgFo2AUjEAAAFiRNiCsUqrXAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0001-7398-6542","institution":"University of Guilan","correspondingAuthor":true,"prefix":"","firstName":"Hossein","middleName":"","lastName":"Roohi","suffix":""}],"badges":[],"createdAt":"2025-08-24 14:44:56","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7446877/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7446877/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11696-026-04733-5","type":"published","date":"2026-03-07T15:59:58+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":104252032,"identity":"8709cb7d-44a4-4623-9f05-287f45fb4ec3","added_by":"auto","created_at":"2026-03-09 16:16:49","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1873576,"visible":true,"origin":"","legend":"","description":"","filename":"MainArticleCP.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7446877/v1_covered_dc498f4e-b1e1-48db-b538-f4ed321762fb.pdf"},{"id":91317105,"identity":"723e7945-a248-42b1-99d4-180a9fc6315d","added_by":"auto","created_at":"2025-09-15 08:30:53","extension":"docx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":18633,"visible":true,"origin":"","legend":"","description":"","filename":"Suppdata.docx","url":"https://assets-eu.researchsquare.com/files/rs-7446877/v1/3a7f9c3fef100fa470f3ddb7.docx"}],"financialInterests":"","formattedTitle":"Substituent and State-Specific Solvent Influences on Novel NIR-Emitting ESIPT-Active Push–Pull Fluorescent Dyes Exhibiting Large Stokes Shifts","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"chemical-papers","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"chpa","sideBox":"Learn more about [Chemical Papers](http://link.springer.com/journal/11696)","snPcode":"11696","submissionUrl":"https://www.editorialmanager.com/CHPA/default.aspx","title":"Chemical Papers","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"ESIPT, NIR dyes, Cyanine, Stokes shift, TD-DFT","lastPublishedDoi":"10.21203/rs.3.rs-7446877/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7446877/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe most attractive features of the ESIPT-cyanine dyes are their potential in molecular imaging, due to their unique photophysical properties, excellent biocompatibility, and high cell penetration ability. This study utilizes the TD-CAM-B3LYP quantum chemical method to investigate the photophysical properties of a series of near-infrared emitting dyes. These dyes are constructed around a central phenol ring that is functionalized with a strongly electron-withdrawing cyanine group (\u0026ndash;CH\u0026thinsp;=\u0026thinsp;CH\u0026ndash;R₂⁺) located ortho to the hydroxyl function, and feature tunable substituents (R₁) at the para position. The S₀ \u0026rarr; S\u003csub\u003e1\u003c/sub\u003e absorption wavelengths for \u003cb\u003eL1\u0026ndash;L4\u003c/b\u003e range approximately from 323 nm (\u003cb\u003eL1\u003c/b\u003e) to 527 nm (\u003cb\u003eL4\u003c/b\u003e) in water and from 329 nm (L1) to 520 nm (\u003cb\u003eL4\u003c/b\u003e) in DCM. Similarly, the emission wavelengths corresponding to the S₁\u0026ndash;E (S₁\u0026ndash;K) forms range from ~\u0026thinsp;406 (~\u0026thinsp;465) nm for \u003cb\u003eL1\u003c/b\u003e up to ~\u0026thinsp;865 (~\u0026thinsp;781) nm for \u003cb\u003eL4\u003c/b\u003e in water and 407 (468) nm to 809 (769) nm in DCM. The calculated Stokes shifts at S\u003csub\u003e1\u003c/sub\u003e-K state for \u003cb\u003eL1-L4\u003c/b\u003e in water and DCM are 141.0 and 138.1 nm for \u003cb\u003eL1\u003c/b\u003e, 297.3 and 257.8 nm for \u003cb\u003eL2\u003c/b\u003e, 249.2 and 243.4 nm for \u003cb\u003eL3\u003c/b\u003e, and 254.6 and 249.1 nm for \u003cb\u003eL4\u003c/b\u003e, respectively. Aligned with recent advances in ESIPT\u0026ndash;cyanine dyes for fluorescence imaging, particularly in targeting acidic organelles such as lysosomes, the push\u0026ndash;pull electron \u003cb\u003eL2\u0026ndash;L4\u003c/b\u003e systems specifically \u003cb\u003eL4\u003c/b\u003e characterized by their large Stokes shifts that reduce self-reabsorption for high-contrast imaging, are anticipated to offer comparable benefits.\u003c/p\u003e","manuscriptTitle":"Substituent and State-Specific Solvent Influences on Novel NIR-Emitting ESIPT-Active Push–Pull Fluorescent Dyes Exhibiting Large Stokes Shifts","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-15 08:30:48","doi":"10.21203/rs.3.rs-7446877/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2025-09-16T11:14:30+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-06T08:42:34+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Chemical Papers","date":"2025-08-28T17:13:48+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-27T03:00:57+00:00","index":"","fulltext":""},{"type":"submitted","content":"Chemical Papers","date":"2025-08-25T01:49:34+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"chemical-papers","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"chpa","sideBox":"Learn more about [Chemical Papers](http://link.springer.com/journal/11696)","snPcode":"11696","submissionUrl":"https://www.editorialmanager.com/CHPA/default.aspx","title":"Chemical Papers","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"e498a467-4791-4cf3-9688-7c75bb8c41ff","owner":[],"postedDate":"September 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-03-09T16:15:08+00:00","versionOfRecord":{"articleIdentity":"rs-7446877","link":"https://doi.org/10.1007/s11696-026-04733-5","journal":{"identity":"chemical-papers","isVorOnly":false,"title":"Chemical Papers"},"publishedOn":"2026-03-07 15:59:58","publishedOnDateReadable":"March 7th, 2026"},"versionCreatedAt":"2025-09-15 08:30:48","video":"","vorDoi":"10.1007/s11696-026-04733-5","vorDoiUrl":"https://doi.org/10.1007/s11696-026-04733-5","workflowStages":[]},"version":"v1","identity":"rs-7446877","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7446877","identity":"rs-7446877","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}