{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,9]],"date-time":"2026-01-09T14:08:44Z","timestamp":1767967724364,"version":"3.49.0"},"reference-count":47,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2022,6,29]],"date-time":"2022-06-29T00:00:00Z","timestamp":1656460800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Two novel D-A-\u03c0-A1 metal-free organic dyes of the KEA series containing benzo[d][1,2,3]thiadiazole (isoBT) internal acceptor, indoline donors fused with cyclopentane or cyclohexane rings (D), a thiophene as a \u03c0-spacer, and a cyanoacrylate as an anchor part were synthesized. Monoarylation of 4,7-dibromobenzo[d][1,2,3]thiadiazole by Suzuki-Miyamura cross-coupling reaction showed that in the case of indoline and carbazole donors, the reaction was non-selective, i.e., two monosubstituted derivatives were isolated in each case, whereas only one mono-isomer was formed with phenyl- and 2-thienylboronic acids. This was explained by the fact that heterocyclic indoline and carbazole fragments are much stronger donor groups compared to thiophene and benzene, as confirmed by cyclic voltammetry measurements and calculation of HOMO energies of indoline, carbazole, thiophene and benzene molecules. The structure of monoaryl(hetaryl) derivatives was strictly proven by NMR spectroscopy and X-ray diffraction. The optical and photovoltaic properties observed for the KEA dyes showed that these compounds are promising for the creation of solar cells. A comparison with symmetrical benzo[c][1,2,3]thiadiazole dyes WS-2 and MAX114 showed that the asymmetric nature of benzo[d][1,2,3]thiadiazole KEA dyes leads to a hypsochromic shift of the ICT band in comparison with the corresponding benzo[c][1,2,5]thiadiazole isomers. KEA dyes have a narrow HOMO-LUMO gap of 1.5\u20131.6 eV. Amongst these dyes, KEA321 recorded the best power efficiency (PCE), i.e., 5.17%, which is superior to the corresponding symmetrical benzo[c][1,2,3]thiadiazole dyes WS-2 and MAX114 (5.07 and 4.90%).<\/jats:p>","DOI":"10.3390\/molecules27134197","type":"journal-article","created":{"date-parts":[[2022,6,29]],"date-time":"2022-06-29T22:43:28Z","timestamp":1656542608000},"page":"4197","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Novel D-A-\u03c0-A1 Type Organic Sensitizers from 4,7-Dibromobenzo[d][1,2,3]thiadiazole and Indoline Donors for Dye-Sensitized Solar Cells"],"prefix":"10.3390","volume":"27","author":[{"given":"Nikita S.","family":"Gudim","sequence":"first","affiliation":[{"name":"N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9893-292X","authenticated-orcid":false,"given":"Ekaterina A.","family":"Knyazeva","sequence":"additional","affiliation":[{"name":"N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia"},{"name":"Nanotechnology Education and Research Center, South Ural State University, 454080 Chelyabinsk, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ludmila V.","family":"Mikhalchenko","sequence":"additional","affiliation":[{"name":"N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maksim S.","family":"Mikhailov","sequence":"additional","affiliation":[{"name":"Nanotechnology Education and Research Center, South Ural State University, 454080 Chelyabinsk, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lu","family":"Zhang","sequence":"additional","affiliation":[{"name":"EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Neil","family":"Robertson","sequence":"additional","affiliation":[{"name":"EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6609-4087","authenticated-orcid":false,"given":"Oleg A.","family":"Rakitin","sequence":"additional","affiliation":[{"name":"N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,6,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"6841","DOI":"10.1021\/ic0508371","article-title":"Solar Energy Conversion by Dye-Sensitized Photovoltaic Cells","volume":"44","year":"2005","journal-title":"Inorg. Chem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2474","DOI":"10.1002\/anie.200804709","article-title":"Metal-Free Organic Dyes for Dye-Sensitized Solar Cells: From Structure: Property Relationships to Design Rules","volume":"48","author":"Mishra","year":"2009","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"6595","DOI":"10.1021\/cr900356p","article-title":"Dye-Sensitized Solar Cells","volume":"110","author":"Hagfeldt","year":"2010","journal-title":"Chem. Rev."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"372","DOI":"10.1038\/nphoton.2017.60","article-title":"Dye-sensitized solar cells for efficient power generation under ambient lighting","volume":"11","author":"Freitag","year":"2017","journal-title":"Nat. Photonics"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"10720","DOI":"10.1021\/ja801942j","article-title":"Enhance the Optical Absorptivity of Nanocrystalline TiO2 Film with High Molar Extinction Coefficient Ruthenium Sensitizers for High Performance Dye-Sensitized Solar Cells","volume":"130","author":"Gao","year":"2008","journal-title":"J. Am. Chem. Soc."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2618","DOI":"10.1021\/jp8083748","article-title":"Efficient Electron Transfer Ruthenium Sensitizers for Dye-Sensitized Solar Cells","volume":"113","author":"Jin","year":"2009","journal-title":"J. Phys. Chem. C"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"348","DOI":"10.1016\/j.dyepig.2018.04.005","article-title":"Effect of terthiophene spacer position in Ru(II) bipyridyl complexes on the photocurrent and photovoltage for high efficiency dye-sensitized solar cells","volume":"156","author":"Elmorsy","year":"2018","journal-title":"Dye. Pigment."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1038\/nchem.1861","article-title":"Dye-sensitized solar cells with 13% efficiency achieved through the molecular engineering of porphyrin sensitizers","volume":"6","author":"Mathew","year":"2014","journal-title":"Nat. Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2186","DOI":"10.1039\/C8SC04969F","article-title":"Efficient solar cells sensitized by a promising new type of porphyrin: Dye-aggregation suppressed by double strapping","volume":"10","author":"Zeng","year":"2019","journal-title":"Chem. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"9910","DOI":"10.1021\/jacs.9b03302","article-title":"Renaissance of Fused Porphyrins: Substituted Methylene-Bridged Thiophene-Fused Strategy for High-Performance Dye-Sensitized Solar Cells","volume":"141","author":"Kurumisawa","year":"2019","journal-title":"J. Am. Chem. Soc."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"3799","DOI":"10.1021\/jacs.5b01537","article-title":"Donor\/Acceptor Indenoperylene Dye for Highly Efficient Organic Dye-Sensitized Solar Cells","volume":"137","author":"Yao","year":"2015","journal-title":"J. Am. Chem. Soc."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"23225","DOI":"10.1039\/C9TA09025H","article-title":"Tetraphenylethylene tethered phenothiazine-based double-anchored sensitizers for high performance dye-sensitized solar cells","volume":"7","author":"Li","year":"2019","journal-title":"J. Mater. Chem. A"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1216","DOI":"10.1021\/acsphotonics.9b00092","article-title":"Phenalenothiophene-Based Organic Dye for Stable and Efficient Solar Cells with a Cobalt Redox Electrolyte","volume":"6","author":"Wu","year":"2019","journal-title":"ACS Photonics"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"10379","DOI":"10.1039\/C9TC03066B","article-title":"Effect of structural engineering of \u03c0-spacers on anti-aggregation of D\u2013A\u2013\u03c0\u2013A dyes","volume":"7","author":"Hua","year":"2019","journal-title":"J. Mater. Chem. C"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"23810","DOI":"10.1039\/C4RA16493H","article-title":"Recent progress in organic sensitizers for dye-sensitized solar cells","volume":"5","author":"Lee","year":"2015","journal-title":"RSC Adv."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"14518","DOI":"10.1039\/C8TA02281J","article-title":"Rational design criteria for D\u2013\u03c0\u2013A structured organic and porphyrin sensitizers for highly efficient dye-sensitized solar cells","volume":"6","author":"Ji","year":"2018","journal-title":"J. Mater. Chem. A"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1059","DOI":"10.1039\/C6QM00271D","article-title":"Improvement of D\u2013\u03c0\u2013A organic dye-based dye-sensitized solar cell performance by simple triphenylamine donor substitutions on the \u03c0-linker of the dye","volume":"1","author":"Prachumrak","year":"2017","journal-title":"Mater. Chem. Front."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1039\/C4MH00102H","article-title":"Heteroannulated acceptors based on benzothiadiazole","volume":"2","author":"Parker","year":"2015","journal-title":"Mater. Horizons"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2039","DOI":"10.1039\/C2CS35346F","article-title":"Organic sensitizers from D\u2013\u03c0\u2013A to D\u2013A\u2013\u03c0\u2013A: Effect of the internal electron-withdrawing units on molecular absorption, energy levels and photovoltaic performances","volume":"42","author":"Wu","year":"2013","journal-title":"Chem. Soc. Rev."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1822","DOI":"10.1021\/am3001049","article-title":"D-A-\u03c0-A Featured Sensitizers Bearing Phthalimide and Benzotriazole as Auxiliary Acceptor: Effect on Absorption and Charge Recombination Dynamics in Dye-Sensitized Solar Cells","volume":"4","author":"Li","year":"2012","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"9307","DOI":"10.1021\/acsami.5b02475","article-title":"Insight into D\u2013A\u2212\u03c0\u2013A Structured Sensitizers: A Promising Route to Highly Efficient and Stable Dye-Sensitized Solar Cells","volume":"7","author":"Wu","year":"2015","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"152230","DOI":"10.1016\/j.tetlet.2020.152230","article-title":"Fused 1,2,5-thia- and 1,2,5-selenadiazoles: Synthesis and application in materials chemistry","volume":"61","author":"Rakitin","year":"2020","journal-title":"Tetrahedron Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1146","DOI":"10.1070\/RCR4649","article-title":"Influence of structural factors on the photovoltaic properties of dye-sensitized solar cells","volume":"85","author":"Knyazeva","year":"2016","journal-title":"Russ. Chem. Rev."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"855","DOI":"10.1007\/s10593-017-2137-2","article-title":"4,7-Dibromo-substituted 2,1,3-benzothia(selena,oxa)diazoles and [1,2,5]thia(selena)diazolo[3,4-c]pyridines as building blocks in solar cells components (microreview)","volume":"53","author":"Knyazeva","year":"2017","journal-title":"Chem. Heterocycl. Compd."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"475","DOI":"10.1080\/00304948.2014.963454","article-title":"Recent Developments in the Synthesis and Applications of 1,2,5-Thia- and Selenadiazoles. A Review","volume":"46","author":"Konstantinova","year":"2014","journal-title":"Org. Prep. Proc. Int."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"6390","DOI":"10.1021\/acs.chemmater.6b02813","article-title":"Benzo[d][1,2,3]thiadiazole (isoBT): Synthesis, Structural Analysis, and Implementation in Semiconducting Polymers","volume":"28","author":"Chen","year":"2016","journal-title":"Chem. Mater."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Gudim, N.S., Knyazeva, E.A., Mikhalchenko, L.V., Golovanov, I.S., Popov, V.V., Obruchnikova, N.V., and Rakitin, O.A. (2021). Benzothiadiazole vs. iso-Benzothiadiazole: Synthesis, Electrochemical and Optical Properties of D\u2013A\u2013D Conjugated Molecules Based on Them. Molecules, 26.","DOI":"10.3390\/molecules26164931"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Gudim, N.S., Knyazeva, E.A., Obruchnikova, N.V., Rakitin, O.A., and Popov, V.V. (2021). 4-(7-Bromobenzo[d][1,2,3]thiadiazol-4-yl)morpholine. Molbank, 2021.","DOI":"10.3390\/M1202"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1016\/j.tet.2012.10.043","article-title":"Synthesis and photophysical properties of fluorescent 2,1,3-benzothiadiazole-triazole-linked glycoconjugates: Selective chemosensors for Ni(II)","volume":"69","author":"Moro","year":"2013","journal-title":"Tetrahedron"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"608","DOI":"10.1007\/s10593-017-2099-4","article-title":"Suzuki cross-coupling reactions of 4,7-dibromo[1,2,5]selenadiazolo[3,4-c]pyridine\u2014A path to new solar cell components","volume":"53","author":"Knyazeva","year":"2017","journal-title":"Chem. Heterocycl. Comp."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3766","DOI":"10.1021\/ja209331y","article-title":"Pyridalthiadiazole-Based Narrow Band Gap Chromophores","volume":"134","author":"Henson","year":"2012","journal-title":"J. Am. Chem. Soc."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"4459","DOI":"10.1016\/j.jorganchem.2006.02.015","article-title":"Computational study of the transmetalation process in the Suzuki\u2013Miyaura cross-coupling of aryls","volume":"691","author":"Braga","year":"2006","journal-title":"J. Organomet. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"7437","DOI":"10.1016\/j.tet.2008.05.018","article-title":"Mechanistic insights into the transmetalation step of a Suzuki\u2013Miyaura reaction of 2(4)-bromopyridines: Characterization of an intermediate","volume":"64","author":"Sicre","year":"2008","journal-title":"Tetrahedron"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2367","DOI":"10.1002\/adma.201004554","article-title":"Electrochemical Considerations for Determining Absolute Frontier Orbital Energy Levels of Conjugated Polymers for Solar Cell Applications","volume":"23","author":"Cardona","year":"2011","journal-title":"Adv. Mater."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"8895","DOI":"10.1039\/c3cs60257e","article-title":"Polymers for electronics and spintronics","volume":"42","author":"Bujak","year":"2013","journal-title":"Chem. Soc. Rev."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1002\/aenm.201100341","article-title":"Hexylthiophene-Featured D-A-\u03c0-A Structural Indoline Chromophores for Coadsorbent-Free and Panchromatic Dye-Sensitized Solar Cells","volume":"2","author":"Wu","year":"2012","journal-title":"Adv. Energy Mater."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"112333","DOI":"10.1016\/j.jphotochem.2019.112333","article-title":"9-(p-Tolyl)-2,3,4,4a,9,9a-hexahydro-1H-carbazole\u2014A new donor building-block in the design of sensitizers for dye-sensitized solar cells","volume":"391","author":"Mikhailov","year":"2020","journal-title":"J. Photochem. Photobiol. A Chem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"6867","DOI":"10.1021\/jp004411d","article-title":"Pseudohalogens for Dye-Sensitized TiO2 Photoelectrochemical Cells","volume":"105","author":"Oskam","year":"2001","journal-title":"J. Phys. Chem. B"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"256","DOI":"10.1016\/j.electacta.2015.04.071","article-title":"Simple Metal-Free Dyes Derived from Triphenylamine for DSSC: A Comparative Study of Two Different Anchoring Group","volume":"169","author":"Narayanaswamy","year":"2015","journal-title":"Electrochim. Acta"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Gudim, N., Mikhailov, M., Knyazeva, E.A., Almenningen, D.M., Mikhalchenko, L.V., Economopoulos, S., and Rakitin, O.A. (2022). Monitoring the dependence of photovoltaic properties of dye-sensitized solar cells from the structure of D-A-\u03c0-A type sensitizers with 9-(p-tolyl)-2,3,4,4a,9,9a-hexahydro-1H-1,4-methanocarbazole donor building block. Mol. Syst. Des. Eng., 7.","DOI":"10.1039\/D2ME00025C"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"10771","DOI":"10.1039\/c2jm30978e","article-title":"Donor\u2013acceptor dyes incorporating a stable dibenzosilole \u03c0-conjugated spacer for dye-sensitized solar cells","volume":"22","author":"Akhtaruzzaman","year":"2012","journal-title":"J. Mater. Chem."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"94","DOI":"10.1038\/pj.2013.83","article-title":"Synthesis and fluorescent properties of conjugated co-oligomers containing maleimide and carbazole units at the main chain","volume":"46","author":"Nakamura","year":"2014","journal-title":"Polym. J."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"2831","DOI":"10.1016\/j.tet.2006.01.013","article-title":"Methodology for the synthesis of 1,2-disubstituted arylnaphthalenes from \u03b1-tetralones","volume":"62","author":"Moleele","year":"2006","journal-title":"Tetrahedron"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"8658","DOI":"10.1021\/ma302133h","article-title":"A selenophene analogue of PCDTBT: Selective fine-tuning of lumo to lower of the bandgap for efficient polymer solar cells","volume":"45","author":"Kim","year":"2012","journal-title":"Macromolecules"},{"key":"ref_45","unstructured":"(2022, April 04). CrysAlisPro. Version 1.171.41.106a. Rigaku Oxford Diffraction. Available online: https:\/\/www.rigaku.com\/products\/crystallography\/crysalis."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1107\/S2053273314026370","article-title":"SHELXT\u2014Integrated space-group and crystal-structure determination","volume":"71","author":"Sheldrick","year":"2015","journal-title":"Acta Crystallogr. Sect. A Found. Adv."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1107\/S2053229614024218","article-title":"Crystal structure refinement with SHELXL","volume":"71","author":"Sheldrick","year":"2015","journal-title":"Acta Crystallogr. Sect. C Struct. Chem."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/27\/13\/4197\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:40:39Z","timestamp":1760139639000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/27\/13\/4197"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,6,29]]},"references-count":47,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2022,7]]}},"alternative-id":["molecules27134197"],"URL":"https:\/\/doi.org\/10.3390\/molecules27134197","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,6,29]]}}}