{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T21:35:15Z","timestamp":1772746515601,"version":"3.50.1"},"reference-count":42,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2022,6,17]],"date-time":"2022-06-17T00:00:00Z","timestamp":1655424000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Sofia University Science Fund","award":["80-10-6\/2022"],"award-info":[{"award-number":["80-10-6\/2022"]}]},{"name":"the Bulgarian Ministry of Education and Science","award":["80-10-6\/2022"],"award-info":[{"award-number":["80-10-6\/2022"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The veterinary 16-membered macrolide antibiotics tylosin (HTyl, 1a) and tilmicosin (HTilm, 1b) react with copper(II) ions in acetone at metal-to-ligand molar ratio of 1:2 to form blue (2) or green (3) metal(II) coordination species, containing nitrate or chloride anions, respectively. The complexation processes and the properties of 2\u20133 were studied by an assortment of physicochemical techniques (UV-Vis, EPR, NMR, FTIR, elemental analysis). The experimental data revealed that the main portion of copper(II) ions are bound as neutral EPR-silent dinuclear complexes of composition [Cu2(\u00b5-NO3)2L2] (2a\u2013b) and [Cu2(\u00b5-Cl)2Cl2(HL)2] (3a\u2013b), containing impurities of EPR-active mono-species [Cu(NO3)L] (2a\u2019\u2013b\u2019) and [CuCl2(HL)] (3a\u2019\u2013b\u2019). The possible structural variants of the dinuclear- and mono-complexes were modeled by the DFT method, and the computed spectroscopic parameters of the optimized constructs were compared to those measured experimentally. Using such a combined approach, the main coordination unit of the macrolides, involved in the complex formation, was defined to be their mycaminosyl substituent, which acts as a terminal ligand in a bidentate mode through the tertiary nitrogen atom and the oxygen from a deprotonated (2) or non-dissociated (3) hydroxyl group, respectively.<\/jats:p>","DOI":"10.3390\/molecules27123899","type":"journal-article","created":{"date-parts":[[2022,6,17]],"date-time":"2022-06-17T11:45:44Z","timestamp":1655466344000},"page":"3899","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Dinuclear vs. Mononuclear Copper(II) Coordination Species of Tylosin and Tilmicosin in Non-Aqueous Solutions"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5624-8369","authenticated-orcid":false,"given":"Ivayla","family":"Pantcheva","sequence":"first","affiliation":[{"name":"Faculty of Chemistry and Pharmacy, Sofia University \u201cSt. Kliment Ohridski\u201d, 1164 Sofia, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Radoslava","family":"Stamboliyska","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry and Pharmacy, Sofia University \u201cSt. Kliment Ohridski\u201d, 1164 Sofia, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nikolay","family":"Petkov","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry and Pharmacy, Sofia University \u201cSt. Kliment Ohridski\u201d, 1164 Sofia, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5405-5037","authenticated-orcid":false,"given":"Alia","family":"Tadjer","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry and Pharmacy, Sofia University \u201cSt. Kliment Ohridski\u201d, 1164 Sofia, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9565-3850","authenticated-orcid":false,"given":"Svetlana","family":"Simova","sequence":"additional","affiliation":[{"name":"Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5815-5131","authenticated-orcid":false,"given":"Radostina","family":"Stoyanova","sequence":"additional","affiliation":[{"name":"Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rositza","family":"Kukeva","sequence":"additional","affiliation":[{"name":"Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4173-548X","authenticated-orcid":false,"given":"Petar","family":"Dorkov","sequence":"additional","affiliation":[{"name":"Research and Development Department, Biovet Ltd., 4550 Peshtera, Bulgaria"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,6,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"594529","DOI":"10.4061\/2011\/594529","article-title":"Copper and its complexes in medicine: A biochemical approach","volume":"2011","author":"Iakovidis","year":"2011","journal-title":"Mol. 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