Contribution of Energy Transfer from the Singlet State to the Sensitization of Eu³⁺ and Tb³⁺ Luminescence by Sulfonylamidophosphates

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• 作者：Ewa Kasprzycka ; Dr. Victor A. Trush ; Prof. Dr. Vladimir M. Amirkhanov ; Dr. Lucjan Jerzykiewicz ; Prof. Dr. Oscar L. Malta ; Prof. Dr. Janina Legendziewicz and Dr. Paula Gawryszewska
• 刊名：Chemistry - A European Journal
• 出版年：2017
• 出版时间：January 26, 2017
• 年：2017
• 卷：23
• 期：6
• 页码：1318-1330
• 全文大小：3454K
• ISSN：1521-3765

文摘

A series of stable lanthanide complexes Na[Ln(L)₄] (Ln=La³⁺, Eu³⁺, Gd³⁺, Tb³⁺, with L=dimethyl(4-methylphenylsulfonyl)amidophosphate and dimethyl-2-naphthylsulfonylamidophosphate) were synthesized. The compounds were characterized by single-crystal X-ray diffraction, IR, absorption, and emission spectroscopy at 293 and 77 K. In contrast to the usual and well-known dominant role of the ligand triplet state in intramolecular energy transfer processes in Ln complexes, in this particular new class of Ln compounds with sulphonylamidophosphate ligands, strong experimental and detailed theoretical evidence suggest a dominant role is played by the ligand first excited singlet state. The importance of the role played by the ⁷F₅ level in the case of the Tb³⁺ compound in this process is shown. The theoretical approach for the energy transfer rates was successfully applied to the rationalization of the experimental data. The higher-lying excited levels of Eu (⁵D_J, ⁵L_J, ⁵G_J) and Tb (⁵D_J, ⁵G_J, ⁵L_J, ⁵H_J, ⁵F_J, ⁵I_J) were included in the calculations for the first time. Both the multipolar and exchange mechanisms were taken into account. The experimental intensity parameters (Ω_λ), emission lifetimes (τ), radiative (A_rad) and non-radiative (A_nrad) decay rates, and quantum yields (theoretical and experimental) were determined and are discussed in detail.