{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,9]],"date-time":"2026-09-09T18:36:59Z","timestamp":1788979019052,"version":"build-2803163510"},"reference-count":33,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2020,11,19]],"date-time":"2020-11-19T00:00:00Z","timestamp":1605744000000},"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>Novel fluorescent dyes such as benzoxazole-boron complexes, bearing \u03b2-ketoiminate ligands, have been synthesized and characterized with a focus on the influence of a substituent on the basic photophysical properties. 1H, 11B, 13C, 15N, and 19F nuclear magnetic resonance (NMR) spectra of substituted 2-phenacylbenzoxazole difluoroboranes have been recorded and discussed. It is worth mentioning that a high correlation coefficient was found between 15N-NMR parameters and substituent constants. The photophysical properties of these new dyes have been investigated by fluorescence and ultraviolet-visible (UV-Vis) absorption spectroscopy. The geometry optimization, vibrational spectra, and the HOMO and LUMO energies were calculated based on density functional theory with the use of the B3LYP functional and 6-311++G(d,p) basis set.<\/jats:p>","DOI":"10.3390\/molecules25225420","type":"journal-article","created":{"date-parts":[[2020,11,19]],"date-time":"2020-11-19T10:46:26Z","timestamp":1605782786000},"page":"5420","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Substituted 2-Phenacylbenzoxazole Difluoroboranes: Synthesis, Structure and Properties"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7286-2692","authenticated-orcid":false,"given":"Agnieszka","family":"Skotnicka","sequence":"first","affiliation":[{"name":"Faculty of Chemical Technology and Engineering, UTP University of Science and Technology, Seminaryjna 3, 85-326 Bydgoszcz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7268-4956","authenticated-orcid":false,"given":"Przemys\u0142aw","family":"Czele\u0144","sequence":"additional","affiliation":[{"name":"Department of Physical Chemistry, Collegium Medicum, N. Copernicus University, Kurpi\u0144skiego 5, 85-950 Bydgoszcz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,11,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4778","DOI":"10.1039\/C4CS00030G","article-title":"Structural modification strategies for the rational design of red\/NIR region BODIPYs","volume":"43","author":"Lu","year":"2014","journal-title":"Chem. Soc. Rev."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"12914","DOI":"10.1039\/C8CC06403B","article-title":"Recent advances in the synthesis of [a]-benzo-fused BODIPY fluorophores","volume":"54","author":"Vasseur","year":"2018","journal-title":"Chem. Commun."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"8904","DOI":"10.1039\/C5CS00364D","article-title":"The triplet excited state of Bodipy: Formation, modulation and application","volume":"44","author":"Zhao","year":"2015","journal-title":"Chem. Soc. Rev."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1347","DOI":"10.1021\/acssensors.8b00262","article-title":"A photoactivatable far-red\/near-infrared BODIPY to monitor cellular dynamics in vivo","volume":"3","author":"Sansalone","year":"2018","journal-title":"ACS Sens."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1130","DOI":"10.1039\/C1CS15132K","article-title":"Fluorescent indicators based on BODIPY","volume":"41","author":"Boens","year":"2012","journal-title":"Chem. Soc. Rev."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3774","DOI":"10.1039\/c3ob42554a","article-title":"Far-red and near infrared BODIPY dyes: Synthesis and applications for fluorescent pH probes and bio-imaging","volume":"12","author":"Ni","year":"2014","journal-title":"Org. Biomol. Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2071","DOI":"10.1016\/j.polymer.2013.02.013","article-title":"BODIPY derivatives and boranil as new photoinitiating systems of cationic polymerization exhibiting a tunable absorption in the 400\u2013600 nm spectral range","volume":"54","author":"Telitel","year":"2013","journal-title":"Polymer"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"6864","DOI":"10.1021\/ma301293m","article-title":"Photopolymerization of cationic monomers and acrylate\/divinylether blends under visible light using pyrromethene dyes","volume":"45","author":"Telitel","year":"2012","journal-title":"Macromolecules"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"43755","DOI":"10.1039\/C6RA03722D","article-title":"Multi-color solid-state emission of \u03b2-iminoenolate boron complexes tuned by methoxyl groups: Aggregation-induced emission and mechanofluorochromism","volume":"6","author":"Zhang","year":"2016","journal-title":"RSC Adv."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1016\/j.dyepig.2017.10.007","article-title":"Mechanofluorochromism of difluoroboron \u03b2-ketoiminate boron complexes functionalized with benzoxazole and benzothiazole","volume":"149","author":"Zhao","year":"2018","journal-title":"Dyes Pigm."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1074812","DOI":"10.1016\/j.dyepig.2019.04.026","article-title":"The impact of the heteroatom in a five-membered ring on the photophysical properties of difluoroborates","volume":"170","author":"Grabarz","year":"2019","journal-title":"Dyes Pigm."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"957","DOI":"10.1016\/j.dyepig.2013.08.002","article-title":"Substituent effects on the photophysical properties of fluorescent 2-benzoylmethylenequinoline difluoroboranes: A combined experimental and quantum chemical study","volume":"99","author":"Zakrzewska","year":"2013","journal-title":"Dyes Pigm."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2072","DOI":"10.1021\/jo502244j","article-title":"Influence of substituent and benzoannulation on photophysical properties of 1-benzoylmethyleneisoquinoline difluoroborates","volume":"80","author":"Zakrzewska","year":"2015","journal-title":"J. Org. Chem."},{"key":"ref_14","first-page":"909","article-title":"C-Mono- and dibenzoylation of 2-methylbenzimidazole with use of benzoyl chloride","volume":"30","author":"Dzvinchuk","year":"1994","journal-title":"Zh. Org. Khim."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4444","DOI":"10.3390\/ijms14034444","article-title":"Synthesis and structural characterization of substituted 2-phenacylbenzoxazoles","volume":"14","author":"Skotnicka","year":"2013","journal-title":"Int. J. Mol. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"4682","DOI":"10.1021\/ol302179r","article-title":"Synthesis and fluorescence properties of thiazole-boron complexes bearing a \u03b2-ketoiminate ligand","volume":"14","author":"Kubota","year":"2012","journal-title":"Org. Lett."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1021\/cr00002a004","article-title":"A survey of Hammett substituent constants and resonance and field parameters","volume":"91","author":"Hansch","year":"1991","journal-title":"Chem. Rev."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3597","DOI":"10.1021\/ic300077g","article-title":"Aromatic difluoroboron \u03b2-diketonate complexes: Effects of \u03c0-conjugation and media on optical properties","volume":"52","author":"Xu","year":"2013","journal-title":"Inorg. Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1016\/j.jlumin.2019.02.026","article-title":"Synthesis, photophysical, solvatochromic and DFT studies of (Z)-2-(2-Phenyl-4H-benzo[4,5]thiazolo[3,2-a]pyrimidin-4-ylidene)acetonitrile derivatives","volume":"210","author":"Patil","year":"2019","journal-title":"J. Lumin."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1016\/j.jlumin.2016.12.049","article-title":"Exploration of spectroscopic properties of solvated tris(thenoyltrifluoroacetonate)(2,2\u2032-bipyridine)europium(III)red hybrid organic complex for solution processed OLEDs and displays","volume":"185","author":"Chitnis","year":"2017","journal-title":"J. Lumin."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/j.molstruc.2016.01.068","article-title":"Molecular structure, vibrational spectral assignments (FT-IR and FT-RAMAN), NMR, NBO, HOMO-LUMO and NLO properties of O-methoxybenzaldehyde based on DFT calculations","volume":"1111","author":"Vennila","year":"2016","journal-title":"J. Mol. Struct."},{"key":"ref_22","unstructured":"Silverstein, R.M., and Webster, F.X. (1998). Spectroscopic Identification of Organic Compound, John Willey & Sons. [6th ed.]."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3580","DOI":"10.1021\/jp013084m","article-title":"A new approach to vibrational analysis of large molecules by density functional theory: Wavenumber-linear scaling method","volume":"106","author":"Yoshida","year":"2002","journal-title":"J. Phys. Chem. A"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/0047-2670(83)80061-6","article-title":"Photophysics of some common fluorescence standards","volume":"23","author":"Meech","year":"1983","journal-title":"J. Photochem."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2213","DOI":"10.1351\/PAC-REP-10-09-31","article-title":"Standards for photoluminescence quantum yield measurements in solution (IUPAC Technical Report)","volume":"83","author":"Brouwer","year":"2011","journal-title":"Pure Appl. Chem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1021\/j100248a024","article-title":"Solvent effects on emission yield and lifetime for coumarin laser dyes. Requirements for a rotatory decay mechanism","volume":"89","author":"Jones","year":"1985","journal-title":"J. Phys. Chem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1103\/PhysRevB.37.785","article-title":"Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density","volume":"37","author":"Lee","year":"1988","journal-title":"Phys. Rev. B"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"5648","DOI":"10.1063\/1.464913","article-title":"Density-functional thermochemistry. III. The role of exact exchange","volume":"98","author":"Becke","year":"1993","journal-title":"J. Chem. Phys."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/j.synthmet.2014.05.015","article-title":"Evaluation of various density functionals for predicting the electrophosphorescent host HOMO, LUMO and triplet energies","volume":"195","author":"Ong","year":"2014","journal-title":"Synth. Met."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2193","DOI":"10.1063\/1.455064","article-title":"A complete basis set model chemistry. I. The total energies of closed-shell atoms and hydrides of the first-row elements","volume":"89","author":"Petersson","year":"1988","journal-title":"J. Chem. Phys."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"6081","DOI":"10.1063\/1.460447","article-title":"A complete basis set model chemistry. II. Open-shell systems and the total energies of the first-row atoms","volume":"94","author":"Petersson","year":"1991","journal-title":"J. Chem. Phys."},{"key":"ref_32","unstructured":"Frisch, D.J., Trucks, M.J., Schlegel, G.W., Scuseria, H.B., Robb, G.E., Cheeseman, M.A., Scalmani, J.R., Barone, G., Petersson, V., and Nakatsuji, G.A. (2016). Gaussian 09 (Revision A. 02), Gaussian, Inc."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1186\/1758-2946-4-17","article-title":"Avogadro: An advanced semantic chemical editor, visualization, and analysis platform","volume":"4","author":"Hanwell","year":"2012","journal-title":"J. Cheminform."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/25\/22\/5420\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:34:29Z","timestamp":1760178869000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/25\/22\/5420"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,11,19]]},"references-count":33,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2020,11]]}},"alternative-id":["molecules25225420"],"URL":"https:\/\/doi.org\/10.3390\/molecules25225420","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,11,19]]}}}