Brilliant Photoluminescence and Triboluminescence from Ternary Complexes of Dy^III and Tb^III with 3-Phenyl-4-propanoyl-5-isoxazolonate and a Bidentate Phosphine Oxide Coligand

Abstract

Three new lanthanide heterocyclic β-diketonate complexes [Dy(PPI) 3 (EtOH) 2 ] (1), [Dy(PPI) 3 (DPEPO)] (2), and [Tb(PPI) 3 (DPEPO)] (3) [where HPPI = 3-phenyl-4-p r o p a n o y l -5 -i s o x a z o l o n e a n d D P E P O = b i s ( 2 -(diphenylphosphino)phenyl)ether oxide] have been synthesized and fully characterized. Single-crystal X-ray diffraction analyses reveal that these complexes are mononuclear and that the central Ln III ion is coordinated to eight oxygen atoms that are provided by three bidentate β-diketonate ligands and ethanol or bidentate DPEPO in a distorted square antiprismatic geometry. These complexes have high molar absorption coefficients (up to 3 × 10 4 M −1 cm −1 at 285 nm) and display strong visible and, for Dy III , NIR luminescence upon irradiation at the ligand-centered band in the range 250−350 nm. The emission quantum yields and the luminescence lifetimes at room temperature are 3 ± 0.5% and 15 ± 1 μs for 1, 12 ± 2% and 33 ± 1 μs for 2, and 42 ± 6% and 795 ± 1 μs for 3. Moreover, the crystals of 2 and 3 exhibit brilliant triboluminescence, visible in daylight.

Synthesis, crystal structure and luminescent properties of a new samarium-fluorescein metal-organic framework

“…9) which overlaps with the excitation spectrum of the MOF, indicating the energy transfer from ligand (fluorescein) to Sm 3þ . Thus the coordination and sensitization of Sm 3þ ions to fluorescein molecules are confirmed [19]. The emission spectra of the synthesized MOF at different excitation wavelengths are shown in Fig.…”

Dy3+-doped yttrium complex molecular crystals for two-color thermometry in heterogeneous materials

“…First we observe that while the addition of the DPEPO ligand to the Dy:Y(acac) 3 system improves the material's fluorescence lifetimes, the addition of the phen ligand decreases the performance of the Dy:Y(acac) 3 system. This observation is consistent with previous observations on the influence of the phen ligand on Dy(acac) 3 [32] and on other lanthanide-doped complexes [23,47] as well as the influence of DPEPO on other lanthanide-doped complexes [33,34,37,48]. Additionally, we find that when we substitute hfa for acac in Dy:Y(acac) 3 (DPEPO) the fluorescence lifetime drastically decreases, despite the H-F substitution of the acac ligand.…”

“…This implies that the DPEPO ligand improves the performance of the Dy complex, while the phen ligand decreases the performance. These results are consistent with previous studies involving these ligands where phen was observed to decrease the performance of ternary complexes [23,32,47], while DPEPO improved the performance [33,34,37,48]. Phen's negative effect is attributed to its relatively low triplet level [32,47], while DPEPO's enhancing effect is attributed to its compact rigid structure [34].…”

Effective Photo‐ and Triboluminescent Europium(III) Coordination Polymers with Rigid Triangular Spacer Ligands

“…[14,15] Molecular crystalsc omposed of lanthanide complexesa nd coordination polymers have recently been studied for effective triboluminescence. [16][17][18][19][20] While there have been extensived iscussions on the origin of triboluminescence from molecular crystals, somes tudies have indicatedacontribution of the piezoelectric effect upon breaking non-centrosymmetric bulk crystals. [21] The Eu III coordination polymers with triangular spacers in Figure 1a,b are expected to provide close packed structures and effective crystal cracking under mechanical stress.…”