145634 20260217205537.0 doi 10.3390/inorganics12100271 sideral 140555 ART-2024-140555 eng Martínez, Miguel Different Patterns of Pd-Promoted C-H Bond Activation in (Z)-4-Hetarylidene-5(4H)-oxazolones and Consequences in Photophysical Properties 2024 Access copy available to the general public Unrestricted This work aims to amplify the fluorescence of (Z)-4-hetarylidene-5(4H)-oxazolones 1 by suppression of the hula-twist non-radiative deactivation pathway by C^N-orthopalladation of the 4-hetarylidene ring. Different (Z)-4-hetarylidene-2-phenyl-5(4H)-oxazolones, 1a–1c, prepared by the Erlenmeyer–Plöchl method, have been studied. The orthopalladation of (Z)-2-phenyl-4-(5-thiazolylmethylene)-5(4H)-oxazolone (1a) takes place by C-H bond activation of the H4 of the heterocycle and C^N-chelation, giving the dinuclear trifluoroacetate derivative 2a. By further metathesis of bridging ligands in 2a, complexes containing the orthometalated oxazolone and a variety of ligands 3a–5a, were prepared. The study of the photophysical properties of 1a–5a shows that the bonding of the Pd metal to the 4-hetaryliden-5(4H)-oxazolone does not promote, in these cases, an increase in fluorescence. Interestingly, the orthopalladation of (Z)-2-phenyl-4-(4-thiazolylmethylene)-5(4H)-oxazolone (1b) gives orthopalladated 2b, where the incorporation of the Pd to the oxazolone takes place by C-H bond activation of the ortho-H2 of the 2-phenyl group, ring opening of the oxazolone heterocycle and simultaneous N,N-bonding of the N atoms of the thiazole ring and the generated benzamide fragment. This N^N^C-tridentate dianionic bonding mode is obtained for the first time in oxazolones. Despite a similar lock of the hula-twist deactivation, 2b does not show fluorescence. info:eu-repo/grantAgreement/ES/DGA/E07-23R info:eu-repo/grantAgreement/ES/DGA/E17-23R info:eu-repo/grantAgreement/ES/MICINN AEI/PID2022-136861NB-I00 info:eu-repo/grantAgreement/ES/MICINN/PID2019-106394GB-I00 info:eu-repo/grantAgreement/ES/MICINN/PID2021-122869NB-I00 info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es 3.0 2024 CHEMISTRY, INORGANIC & NUCLEAR 16 / 43 = 0.372 2024 Q2 T2 0.509 2024 Inorganic Chemistry 2024 Q2 4.1 2024 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Dalmau, David Crespo, Olga Universidad de Zaragoza (orcid)0000-0001-9522-5840 García-Orduña, Pilar (orcid)0000-0002-7063-1292 Lahoz, Fernando (orcid)0000-0001-8054-2237 Martín, Antonio (orcid)0000-0002-4808-574X Urriolabeitia, Esteban P. (orcid)0000-0001-9779-5820 2010 760 Universidad de Zaragoza Dpto. Química Inorgánica Área Química Inorgánica 12, 10 (2024), 271 [16 pp.] Inorganics 2304-6740 2252442 http://zaguan.unizar.es/record/145634/files/texto_completo.pdf Versión publicada 2737805 http://zaguan.unizar.es/record/145634/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:145634 articulos driver 2026-02-17-20:34:52 ARTICLE