Visible and NIR emitting Yb() and Er() complexes sensitized by β-diketonates and phenanthroline derivatives

• Published in: RSC advances 2020-07, Vol.1 (46), p.27815-27823
• Main Authors: Brito-Santos, Gabriela, Gil-Hernández, Beatriz, Martín, Inocencio R, Guerrero-Lemus, Ricardo, Sanchiz, Joaquín
• Format: Article
• Language: English
• Subjects: Chemistry; Crystal structure; Crystallography; Crystals; Derivatives; Diffraction patterns; Diketones; Erbium; Gadolinium; Molecular structure; Photoluminescence; Single crystals; Ytterbium
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d0ra05539e

Five new complexes namely, [Er(bta) 3 (me-phen)] ( 1 ), [Yb(bta) 3 (me-phen)] ( 2 ), [Gd(bta)3(me-phen)] ( 3 ), [Yb(bta) 3 (pyz-phen)] ( 4 ), and [Er(tta) 3 (pyz-phen)] ( 5 ) have been prepared with the fluorinated β-diketone ligands Hbta and Htta (Hbta = benzoyltrifluoroacetone and Htta = 2-thenoyltrifluoroacetone) combined with the azacyclo phenanthroline-derivatives, 5-methyl-1,10-phenanthroline (me-phen) and pyrazino[2,3- f ][1,10]phenanthroline (pyz-phen). The crystal structures of 2 , 4 and 5 have been solved by single-crystal X-ray diffraction. PXRD patterns show that 1-3 are isostructural. All the compounds exhibit a molecular structure with the metal atom in an eight-coordination geometry. The photophysical processes involved in the photoluminescence of the complexes are investigated; as a result, the radiative lifetimes ( τ Ln ), the 4f-4f emission quantum efficiencies ( Φ Ln ) and the energy-levels diagram are calculated. Long lifetimes and high quantum yields are obtained in the reported complexes.