resumo
Lanthanide complexes with efficient antenna effect and multifunctional optical-magnetic activity are very appropriate for potential applications. Multidentate ligands efficiently sensitizing emission of different lanthanide ions are rare and complexes often suffer from bleaching. Presented here are photostable lanthanide complexes with single-magnet behavior as the first example in which, using the same sensitizer and the same excitation wavelength, extremely high overall emission quantum yields are achieved for various lanthanide ions (QLEu =QLTb = 98%,QLSm = 11%,QLDy = 17%). This is confirmed through computational and experimental analyses. We rationalize the process of energy transfer from the ligand to Eu3+, which was firstly understood in lanthanide compounds withN-phosphorylated carboxamides. The results revealed that in addition to the refractive index, the energy of the ligand triplet state and donor-acceptor distance, overall emission quantum yield is also a function of triplet state lifetime. It is demonstrated how proper design of the energetic and structural properties of the sensitizer and the introduction of excess Na ions into the structure of Ln complexes allow obtaining extremely efficient light converting molecular devices with single-ion magnet behavior.
palavras-chave
ENERGY-TRANSFER; MOLECULE MAGNET; LUMINESCENCE PROPERTIES; COORDINATION-COMPOUNDS; PHOTOPHYSICAL PROPERTIES; INTENSITY PARAMETERS; 4F-4F TRANSITIONS; SOLID-STATE; LIGAND; FIELD
categoria
Materials Science; Physics
autores
Pham, YH; Trush, VA; Neto, ANC; Korabik, M; Sokolnicki, J; Weselski, M; Malta, OL; Amirkhanov, VM; Gawryszewska, P
nossos autores
agradecimentos
The authors wish to acknowledge support through the grant of Minister of Science and Higher Education KNOW12, Poland. A. N. C. N. thanks SusPhotoSolutions-Solucoes Fotovoltaicas Sustentaveis, CENTRO-01-0145-FEDER-000005. This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. We thank Dr Boguslaw Macalik from Institute of Low Temperature and Structure Research-Polish Academy of Sciences for measuring the dependence of refractive index of Na2EuL4 vs. wavelength.