{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T19:15:19Z","timestamp":1790795719249,"version":"4.1.0"},"reference-count":52,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2023,3,22]],"date-time":"2023-03-22T00:00:00Z","timestamp":1679443200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Science, Technological Development and Innovation of Republic of Serbia","award":["451-03-47\/2023-01\/200051"],"award-info":[{"award-number":["451-03-47\/2023-01\/200051"]}]},{"name":"Ministry of Science, Technological Development and Innovation of Republic of Serbia","award":["N62902-22-1-2024"],"award-info":[{"award-number":["N62902-22-1-2024"]}]},{"name":"Office of Naval Research Global","award":["451-03-47\/2023-01\/200051"],"award-info":[{"award-number":["451-03-47\/2023-01\/200051"]}]},{"name":"Office of Naval Research Global","award":["N62902-22-1-2024"],"award-info":[{"award-number":["N62902-22-1-2024"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The self-assembly reaction of the neutral dicyano-bis(1,10-phenanthroline) iron(II) complex with lanthanide ions (Ln = Eu(III), Gd(III), Er(III)) provided two different classes of heterometallic cyano-bridged 3d-4f architectures depending on the nature of the counteranion, irrespective of the size of the 4f metal ion. Tetranuclear oligomers with a squared Fe2Ln2 core were isolated when using nitrate salts, whereas unusual 1D polymeric chains were obtained when resorting to triflate salts under the same synthetic conditions. It is shown that the different structural motifs have a remarkable impact on the thermal stability and the optical properties of the compounds, which display a notable optical ipsochromism of the parent Fe(II) complex upon coordination with the Ln ion. This effect is significantly more pronounced in the polymeric chain than in the Fe2Ln2 oligomer both in solution and in the solid state. Structural evidence suggests that this behavior is likely related to the geometry of the CN-Ln bridge. On the other hand, more extended \u03c0-stacking interactions in the oligomer give rise to a broad charge-transfer absorption (600\u20131500 nm), making this compound promising as NIR absorber. Density Functional Theory calculations and electrochemical studies demonstrate that the observed negative chromism originates from the stabilization of a mixed metal\/cyanide character HOMO with respect to a phenanthroline-centered LUMO.<\/jats:p>","DOI":"10.3390\/molecules28062871","type":"journal-article","created":{"date-parts":[[2023,3,23]],"date-time":"2023-03-23T02:35:26Z","timestamp":1679538926000},"page":"2871","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Anion-Induced Structural Diversity and Optical Chromism in a Series of Cyano-Bridged Heterometallic 3d-4f Coordination Polymers"],"prefix":"10.3390","volume":"28","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3773-2806","authenticated-orcid":false,"given":"Flavia","family":"Artizzu","sequence":"first","affiliation":[{"name":"Dipartimento per lo Sviluppo Sostenibile e la Transizione Ecologica (DiSSTE), Universit\u00e0 del Piemonte Orientale \u201cA. Avogadro\u201d, Piazza S. Eusebio 5, 13100 Vercelli, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8753-7094","authenticated-orcid":false,"given":"Luca","family":"Pilia","sequence":"additional","affiliation":[{"name":"Dipartimento di Ingegneria Meccanica Chimica e dei Materiali, Universit\u00e0 di Cagliari, Via Marengo 2, 09123 Cagliari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3476-0636","authenticated-orcid":false,"given":"Angela","family":"Serpe","sequence":"additional","affiliation":[{"name":"Dipartimento di Ingegneria Civile, Ambientale e Architettura, INSTM Research Unit, Universit\u00e0 di Cagliari, Via Marengo 2, 09123 Cagliari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dimitrije","family":"Mara","sequence":"additional","affiliation":[{"name":"Institute of General and Physical Chemistry, Studentski Trg 12\/V, 11158 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria Francesca","family":"Casula","sequence":"additional","affiliation":[{"name":"Dipartimento di Ingegneria Meccanica Chimica e dei Materiali, Universit\u00e0 di Cagliari, Via Marengo 2, 09123 Cagliari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0025-1104","authenticated-orcid":false,"given":"Luciano","family":"Marchi\u00f2","sequence":"additional","affiliation":[{"name":"Dipartimento SCVSA, Universit\u00e0 di Parma, Parco Area delle Scienze 17\/a, 43124 Parma, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8861-8619","authenticated-orcid":false,"given":"Paola","family":"Deplano","sequence":"additional","affiliation":[{"name":"Dipartimento di Ingegneria Civile, Ambientale e Architettura, INSTM Research Unit, Universit\u00e0 di Cagliari, Via Marengo 2, 09123 Cagliari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4433","DOI":"10.1002\/asia.201900897","article-title":"Heterometallic 3d\u20134f Complexes as Single-Molecule Magnets","volume":"14","author":"Dey","year":"2019","journal-title":"Chem. 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