| Texto completo | |
| Autor(es): |
Assuncao, Israel P.
;
Blois, Lucca
;
Cauli, Flora P.
;
Felinto, Maria Claudia F. C.
;
Malta, Oscar L.
;
Brito, Hermi F.
Número total de Autores: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Alloys and Compounds; v. 1002, p. 11-pg., 2024-07-02. |
| Resumo | |
New tetrakis Lanthanide(III) carboxylate-based complexes (Ln3+: Eu and Tb) were successfully synthesized via a facile one-pot method with flufenamic acid (fluf) as ligand and benzimidazole (Bzim) or 1-ethyl-3-methylimidazole (C2mim) as counterions. In addition, the Q[Tb(fluf)4] complexes (Q+: Bzim and C2mim) were doped into polymethylmethacrylate (PMMA), polystyrene (PS), polycaprolactone (PCL) and poly(9-vinylcarbazole) (PVK) polymeric matrices at a 1 % (w/w) concentration and revealed highly desirable photophysical features such as wide range excitation wavelengths for the PMMA and PCL matrices and a very uncommon emission under sunlight exposure arising from the Tb3+ ion for the PMMA material. Thus, the tetrakis compounds with general formula Q[Ln(fluf)4] were characterized by elemental and thermal analysis, ESI-MS mass spectrometry, and FTIR absorption spectroscopy. The PMMA:(1 %)Q[Tb(fluf)4] doped films revealed higher thermal stability than the complexes. The tetrakis Eu3+ complex with Bzim as counterion shows no luminescence either for room or low temperature due to a highly operative low-lying ligand to metal charge transfer (LMCT) state quenching, while the corresponding C2mim-based analogous complex reveals some weak intensity emission, showing very low intrinsic quantum yield (QEuEu) values. On the other hand, the corresponding Tb3+ compounds presented bright green emission for the solid-state complexes and, particularly, for the PMMA:(1 %)Q[Tb(fluf)4] doped films when excited at UVA, UVB, and UVC radiation. Moreover, when the doped PMMA films are exposed to sunlight radiation in an open external environment, a bright green emission arising from the 5D4 -> 7F5 transition from the Tb3+ ion can be seen. In this way, these optical results suggest that the PMMA:(1 %)Q[Tb(fluf)4] luminescent photonic materials can act as versatile and efficient light-converting molecular devices (LCMDs). (AU) | |
| Processo FAPESP: | 21/08111-2 - Materiais conversores de luz à base de terras raras: marcadores luminescentes, sensores e amplificadores ópticos |
| Beneficiário: | Hermi Felinto de Brito |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 20/16795-6 - Processos de transferência de energia intramolecular em complexos beta-dicetonatos de terras raras investigados por espectroscopia de absorção transiente |
| Beneficiário: | Lucca Blois Guimarães |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado Direto |