| Autor: |
Rinas N. Nagimov, Dmitry V. Lapaev, Gulnaz Sh. Gimazetdinova, Nataliya Shamsutdinova, Victor V. Syakaev, Aidar T. Gubaidullin, Asiya R. Mustafina, Sergey N. Podyachev, Svetlana N. Sudakova |
| Rok vydání: |
2017 |
| Předmět: |
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| Zdroj: |
Tetrahedron. 73:5397-5407 |
| ISSN: |
0040-4020 |
| Popis: |
The present work introduces the synthesis and characterization of upper rim dibromo-substituted bis-1,3-diketone calix[4]arenes with hydroxy and propyloxy groups at the lower rim as ligands for Gd3+ and Tb3+ complexes. The dibromo-substitution does not affect 1:1 complex formation with the lanthanide ions arising from their coordination via two 1,3-diketonate groups incorporated at the upper rim of the calix[4]arene. The analysis of the time-resolved luminescence spectra of the Gd3+ complexes clearly demonstrates the notable enhancement of the decay time of the ligand triplet state, while the energy of the triplet state for the new dibromo-bis-1,3-diketones remains practically unchanged versus its non-substituted analogues. The latter tendency points to the heavy-atom effect on the energy transfer from the excited state to vibration levels of the dibromo-substituted ligand resulting in a decreased radiationless decay contribution. Measurements of Tb3+-centered luminescence indicate a better antenna effect (∼1.7) of dibromo-calix[4]arenes compared with its non-substituted counterpart. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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