Abstract
In luminescent lanthanide (Ln(III)) complexes, the yield and the lifetime of triplet excited state of organic ligands are crucial factors that affect the ligands-to-Ln(III) energy transfer efficiency. Such factors are dependent on spin-orbit coupling induced by the Ln(III) ions that mixes different multiplicity states through heavy atom and paramagnetic effects. We investigated the role of these effects on the energy transfer efficiency in synthesized nonanuclear Yb-Gd / Yb-Lu clusters ([Ln9(µ-OH)10(butyl salicylate)16]NO3, Ln9 = YbnGd9-n or YbnLu9-n, n = 0, 1, 3, 7, and 9). Based on the intensity of the fluorescence and phosphorescence of the ligands, the spin-orbit coupling strength was in the order of Yb(III) > Gd(III) > Lu(III). Various photophysical processes affecting the energy transfer efficiency in YbnGd9-n and YbnLu9-n clusters are discussed from the perspective of spin-orbit coupling and give insight in how to optimize energy transfer efficiencies.
Original language | English |
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Pages (from-to) | 170-175 |
Number of pages | 6 |
Journal | Journal of Luminescence |
Volume | 201 |
DOIs | |
Publication status | Published - 1 Sept 2018 |
Funding
This work was partly supported by the Ministry of Education, Science, Sports and Culture , Grant-in-Aid for Young Scientists (A) , 17H04873 , 2017, and Grant-in-Aid for JSPS Fellows , 16J0130507 , 2017. We also thank Dr. Hiroyasu Sato of RIGAKU Corporation for single-crystal X-ray analyses of Yb 9 and Lu 9 clusters. Appendix A
Keywords
- Energy transfer
- Lanthanide clusters
- Lanthanide complexes
- Spin-orbit coupling