Anion-Induced Structural Diversity and Optical Chromism in a Series of Cyano-Bridged Heterometallic 3<i>d</i>-4<i>f</i> Coordination Polymers
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 3<i>d</i>-4<i>f</i> architectures depending on the nature of the co...
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MDPI AG
2023-03-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/28/6/2871 |
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| author | Flavia Artizzu Luca Pilia Angela Serpe Dimitrije Mara Maria Francesca Casula Luciano Marchiò Paola Deplano |
| author_facet | Flavia Artizzu Luca Pilia Angela Serpe Dimitrije Mara Maria Francesca Casula Luciano Marchiò Paola Deplano |
| author_sort | Flavia Artizzu |
| collection | DOAJ |
| description | 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 3<i>d</i>-4<i>f</i> architectures depending on the nature of the counteranion, irrespective of the size of the 4<i>f</i> metal ion. Tetranuclear oligomers with a squared Fe<sub>2</sub>Ln<sub>2</sub> 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 Fe<sub>2</sub>Ln<sub>2</sub> 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 π-stacking interactions in the oligomer give rise to a broad charge-transfer absorption (600–1500 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. |
| first_indexed | 2024-03-11T06:05:57Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-11T06:05:57Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-2ffa3b4f4ff145458fcaf185aff9caa02023-11-17T12:56:23ZengMDPI AGMolecules1420-30492023-03-01286287110.3390/molecules28062871Anion-Induced Structural Diversity and Optical Chromism in a Series of Cyano-Bridged Heterometallic 3<i>d</i>-4<i>f</i> Coordination PolymersFlavia Artizzu0Luca Pilia1Angela Serpe2Dimitrije Mara3Maria Francesca Casula4Luciano Marchiò5Paola Deplano6Dipartimento per lo Sviluppo Sostenibile e la Transizione Ecologica (DiSSTE), Università del Piemonte Orientale “A. Avogadro”, Piazza S. Eusebio 5, 13100 Vercelli, ItalyDipartimento di Ingegneria Meccanica Chimica e dei Materiali, Università di Cagliari, Via Marengo 2, 09123 Cagliari, ItalyDipartimento di Ingegneria Civile, Ambientale e Architettura, INSTM Research Unit, Università di Cagliari, Via Marengo 2, 09123 Cagliari, ItalyInstitute of General and Physical Chemistry, Studentski Trg 12/V, 11158 Belgrade, SerbiaDipartimento di Ingegneria Meccanica Chimica e dei Materiali, Università di Cagliari, Via Marengo 2, 09123 Cagliari, ItalyDipartimento SCVSA, Università di Parma, Parco Area delle Scienze 17/a, 43124 Parma, ItalyDipartimento di Ingegneria Civile, Ambientale e Architettura, INSTM Research Unit, Università di Cagliari, Via Marengo 2, 09123 Cagliari, ItalyThe 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 3<i>d</i>-4<i>f</i> architectures depending on the nature of the counteranion, irrespective of the size of the 4<i>f</i> metal ion. Tetranuclear oligomers with a squared Fe<sub>2</sub>Ln<sub>2</sub> 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 Fe<sub>2</sub>Ln<sub>2</sub> 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 π-stacking interactions in the oligomer give rise to a broad charge-transfer absorption (600–1500 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.https://www.mdpi.com/1420-3049/28/6/2871iron complexeslanthanidesolvatochromismcoordination polymersheterometallic assemblies |
| spellingShingle | Flavia Artizzu Luca Pilia Angela Serpe Dimitrije Mara Maria Francesca Casula Luciano Marchiò Paola Deplano Anion-Induced Structural Diversity and Optical Chromism in a Series of Cyano-Bridged Heterometallic 3<i>d</i>-4<i>f</i> Coordination Polymers Molecules iron complexes lanthanide solvatochromism coordination polymers heterometallic assemblies |
| title | Anion-Induced Structural Diversity and Optical Chromism in a Series of Cyano-Bridged Heterometallic 3<i>d</i>-4<i>f</i> Coordination Polymers |
| title_full | Anion-Induced Structural Diversity and Optical Chromism in a Series of Cyano-Bridged Heterometallic 3<i>d</i>-4<i>f</i> Coordination Polymers |
| title_fullStr | Anion-Induced Structural Diversity and Optical Chromism in a Series of Cyano-Bridged Heterometallic 3<i>d</i>-4<i>f</i> Coordination Polymers |
| title_full_unstemmed | Anion-Induced Structural Diversity and Optical Chromism in a Series of Cyano-Bridged Heterometallic 3<i>d</i>-4<i>f</i> Coordination Polymers |
| title_short | Anion-Induced Structural Diversity and Optical Chromism in a Series of Cyano-Bridged Heterometallic 3<i>d</i>-4<i>f</i> Coordination Polymers |
| title_sort | anion induced structural diversity and optical chromism in a series of cyano bridged heterometallic 3 i d i 4 i f i coordination polymers |
| topic | iron complexes lanthanide solvatochromism coordination polymers heterometallic assemblies |
| url | https://www.mdpi.com/1420-3049/28/6/2871 |
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