3-Phenyl-4-acyl-5-isoxazolonate complex of Tb3+ doped into poly-β-hydroxybutyrate matrix as a promising light-conversion molecular device

Abstract

A novel class of efficient antenna complexes of Tb 3+ based on the use of 3-phenyl-4-acyl-5-isoxazolone ligands has been designed, synthesized, characterized and their photophysical properties evaluated . The new heterocyclic b-diketonate complexes of Tb 3+ exhibit high green luminescence efficiency in the solid state with quantum yields between 59-72%. Furthermore in this work, the synthesis, characterization and luminescent properties of poly-b-hydroxybutyrate (PHB) polymer films doped with Tb 3+ -3-phenyl-4-acyl-5-isoxazolonate complexes at 5, 10, 15 and 20% (mass) are reported. The fact that the luminescent efficiency of doped films is enhanced (quantum yields between 74-86%) compared with precursor samples revealed that the polymer matrix acts as a co-sensitizer for Tb 3+ centers. The luminescence intensity decreases, however, with increasing precursor concentration in the doped PHB to greater than 15% where a saturation effect is observed, indicating that changes in the polymer matrix improve the absorption properties of the film, consequently quenching the luminescent effect. Synthesized luminescent polymers containing Tb 3+ -hetrocyclic b-diketonate complexes showed promising photoluminescence efficiency for applications to polymer light-emitting diodes and active polymer optical fibers.

Brilliant Photoluminescence and Triboluminescence from Ternary Complexes of DyIII and TbIII with 3-Phenyl-4-propanoyl-5-isoxazolonate and a Bidentate Phosphine Oxide Coligand

“…However, this value is only 70% of the value reported for the hydrate [Tb(PPI) 3 (H 2 O) 2 ] (ϕ overall = 59 ± 6%). 15 The loss in emission quantum yield in the presence of ancillary ligands in Tb III complexes is known, and the reason is explained in our previous reports. 22,36 On the other hand, a slight increase in luminescence lifetime is noted, 795 ± 1 μs for 3 compared to 785 ± 1 μs for [Tb(PPI) 3 (H 2 O) 2 ], and might be due to minimization of concentration quenching.…”

“…14 In a previous study, we designed two novel molecules based on isoxazolone, namely, 3-phenyl-4-propanoyl-5-isoxazolone (HPPI) and 4-isobutyryl-3-phenyl-5-isoxazolone (HIBPI), that proved to be highly efficient sensitizers for Tb III luminescence (overall quantum yields = 59−72%) because of the adequate energy of their triplet levels with respect to Tb( 5 D 4 ). 15 One of the main causes of nonradiative deactivation of the Ln III ion is vibronic coupling with coordinated solvent (water) molecules, which dissipate energy nonradiatively in overtones of O−H vibrations. 16 3 (DPEPO)], where Ln = Dy (2) and Tb (3), were prepared using the method described previously.…”

“…16 3 (DPEPO)], where Ln = Dy (2) and Tb (3), were prepared using the method described previously. 15,22 The products were isolated by solvent evaporation and purified by recrystallization from a chloroform/hexane (1:2 v/v) mixture. Crystals suitable for singlecrystal X-ray diffraction experiments were obtained by slow evaporation of saturated solutions of the complexes in EtOH/ CH 2 Cl 2 (1:1) for 1 and MeCN for 2 and 3 and stored at ambient temperature over a period of one month.…”

“…15 Furthermore, the red shifts observed in the PO stretching frequency of DPEPO (1197 cm Figure S2 (Supporting Information). Important experimental parameters for the structure determinations are listed in Table S1 (Supporting Information), and selected bond lengths (Å) and angles (deg) in Table 1 octacoordinated Ln III ions.…”

“…15,22 Data for ϕ overall for solid-state samples of 1−3 have been determined at room temperature by an absolute method and are listed in Table 3. In the case of Dy III , only transitions between 450 and 800 nm have been taken into consideration.…”