{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T07:42:15Z","timestamp":1773819735012,"version":"3.50.1"},"reference-count":54,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2019,11,12]],"date-time":"2019-11-12T00:00:00Z","timestamp":1573516800000},"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>The acid\u2013base properties of two bifunctional 3-hydroxy-4-pyridinone ligands and their chelating capacity towards Zn2+, an essential bio-metal cation, were investigated in NaCl aqueous solutions by potentiometric, UV-Vis spectrophotometric, and 1H NMR spectroscopic titrations, carried out at 0.15 \u2264 I\/mol \u22121 \u2264 1.00 and 288.15 \u2264 T\/K \u2264 310.15. A study at I = 0.15 mol L\u22121 and T = 298.15 K was also performed for other three Zn2+\/Lz\u2212 systems, with ligands belonging to the same family of compounds. The processing of experimental data allowed the determination of protonation and stability constants, which showed accordance with the data obtained from the different analytical techniques used, and with those reported in the literature for the same class of compounds. ESI-MS spectrometric measurements provided support for the formation of the different Zn2+\/ligand species, while computational molecular simulations allowed information to be gained on the metal\u2013ligand coordination. The dependence on ionic strength and the temperature of equilibrium constants were investigated by means of the extended Debye\u2013H\u00fcckel model, the classical specific ion interaction theory, and the van\u2019t Hoff equations, respectively.<\/jats:p>","DOI":"10.3390\/molecules24224084","type":"journal-article","created":{"date-parts":[[2019,11,13]],"date-time":"2019-11-13T09:11:27Z","timestamp":1573636287000},"page":"4084","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Speciation Studies of Bifunctional 3-Hydroxy-4-Pyridinone Ligands in the Presence of Zn2+ at Different Ionic Strengths and Temperatures"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4069-9368","authenticated-orcid":false,"given":"Anna","family":"Irto","sequence":"first","affiliation":[{"name":"Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Universit\u00e0 di Messina, Viale F. Stagno d\u2019Alcontres 31, 98166 Messina, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1380-5380","authenticated-orcid":false,"given":"Paola","family":"Cardiano","sequence":"additional","affiliation":[{"name":"Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Universit\u00e0 di Messina, Viale F. Stagno d\u2019Alcontres 31, 98166 Messina, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9773-4021","authenticated-orcid":false,"given":"Salvatore","family":"Cataldo","sequence":"additional","affiliation":[{"name":"Dipartimento di Fisica e Chimica Emilio Segr\u00e8, ed. 17, Universit\u00e0 di Palermo, Viale delle Scienze, I-90128 Palermo, Italy"}]},{"given":"Karam","family":"Chand","sequence":"additional","affiliation":[{"name":"Centro de Qu\u00edmica Estrutural, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rov\u00edsco Pais 1, 1049-001 Lisboa, Portugal"}]},{"given":"Rosalia","family":"Maria Cigala","sequence":"additional","affiliation":[{"name":"Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Universit\u00e0 di Messina, Viale F. Stagno d\u2019Alcontres 31, 98166 Messina, Italy"}]},{"given":"Francesco","family":"Crea","sequence":"additional","affiliation":[{"name":"Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Universit\u00e0 di Messina, Viale F. Stagno d\u2019Alcontres 31, 98166 Messina, Italy"}]},{"given":"Concetta","family":"De Stefano","sequence":"additional","affiliation":[{"name":"Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Universit\u00e0 di Messina, Viale F. Stagno d\u2019Alcontres 31, 98166 Messina, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4276-7384","authenticated-orcid":false,"given":"Giuseppe","family":"Gattuso","sequence":"additional","affiliation":[{"name":"Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Universit\u00e0 di Messina, Viale F. Stagno d\u2019Alcontres 31, 98166 Messina, Italy"}]},{"given":"Nicola","family":"Muratore","sequence":"additional","affiliation":[{"name":"Dipartimento di Fisica e Chimica Emilio Segr\u00e8, ed. 17, Universit\u00e0 di Palermo, Viale delle Scienze, I-90128 Palermo, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4183-2252","authenticated-orcid":false,"given":"Alberto","family":"Pettignano","sequence":"additional","affiliation":[{"name":"Dipartimento di Fisica e Chimica Emilio Segr\u00e8, ed. 17, Universit\u00e0 di Palermo, Viale delle Scienze, I-90128 Palermo, Italy"}]},{"given":"Silvio","family":"Sammartano","sequence":"additional","affiliation":[{"name":"Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Universit\u00e0 di Messina, Viale F. Stagno d\u2019Alcontres 31, 98166 Messina, Italy"}]},{"given":"M.","family":"Am\u00e9lia Santos","sequence":"additional","affiliation":[{"name":"Centro de Qu\u00edmica Estrutural, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rov\u00edsco Pais 1, 1049-001 Lisboa, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1213","DOI":"10.1016\/j.ccr.2008.01.033","article-title":"Recent developments on 3-hydroxy-4-pyridinones with respect to their clinical applications: Mono and combined ligand approaches","volume":"252","author":"Santos","year":"2008","journal-title":"Coordin. Chem. Rev."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"383","DOI":"10.4155\/fmc.14.162","article-title":"3-hydroxypyridinone derivatives as metal sequestering agents for therapeutic use","volume":"7","author":"Santos","year":"2015","journal-title":"Future Med. 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