Luminescence properties of lanthanide complexes-based molecular alloys

• Published in: Inorganica Chimica Acta Vol. 501; p. 119309
• Main Authors: Maouche, Roza, Belaid, Sabrina, Benmerad, Belkacem, Bouacida, Sofiane, Freslon, Stéphane, Daiguebonne, Carole, Suffren, Yan, Calvez, Guillaume, Bernot, Kevin, Roiland, Claire, Le Pollès, Laurent, Guillou, Olivier
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-02-2020; Elsevier Science Ltd; Elsevier
• Subjects: Chelation; Chemical Sciences; Coordination chemistry; Coordination polymers; Crystal structure; Crystals; Diffusion rate; Lanthanide complexes; Lanthanides; Ligands; Luminescence; Molecular structure; Nitrates; NMR; Nuclear magnetic resonance; Optical properties; Organic chemistry; Phenanthroline; Physical properties; Single crystals; Structural analysis; Thermal stability; Thermodynamic properties; Ultraviolet radiation; Water chemistry; X ray powder diffraction; X-ray diffraction; Yttrium; Phenanthroline; Lanthanide complexes; Thermal stability; Luminescence; Crystal structure
• ISSN: 0020-1693; 1873-3255; 0020-1693
• DOI: 10.1016/j.ica.2019.119309

Lanthanide complex-based molecular alloys can exhibit interesting luminescent properties and can be good candidates for efficient luminescent coordination materials.
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•Lanthanide complexes-based molecular alloys have been evidenced.•Lanthanide complexes with phenanthroline as ligand exhibit remarkable emission in the NIR.•Stacked ligands induces efficient inter-metallic energy transfers.
Six lanthanides complexes with chemical formula [Ln(phen)2(NO3)3] (Ln = Sm(1), Tb(2), Nd(3), Eu(4), Ho(5) and Y(6), phen = 1,10-phenanthroline) were synthesized. 1 and 2 were obtained as single crystals by slow diffusion. Structural characterization was based on single crystal X-ray diffraction and IR and 89Y-NMR spectroscopies. NMR spectroscopic measurements were performed on [Y(phen)2(NO3)3] (6) and [Y0.75Lu0.25(phen)2(NO3)3] (7). Compounds obtained as microcrystalline powders were characterized by powder X-ray diffraction. The complexes crystallize in the monoclinic system, space group P21/n. Each Ln(III) ion is surrounded by four N atoms from two bidentate phenanthroline ligands and six O atoms from three chelating nitrate groups. The phenanthroline ligand provides efficient sensitization of the complexes that exhibit sizeable luminescence under UV irradiation. Thermal properties have been studied. They confirm the absence of water molecules in the crystal structure. The complexes are thermally stable up to 290 °C. Microcrystalline powders of hetero-lanthanide complexes, with global chemical formula [Tb1−xEux(phen)2(NO3)3] (series8) and [Tb1−xGdx(phen)2(NO3)3] (series9) were synthesized. Their photo-physical properties have been investigated. They demonstrate that luminescent molecular alloys can be obtained from lanthanides complexes and not only from hetero-nuclear coordination polymers as previously reported.