Energy-transfer mechanism in photoluminescent Terbium(III) complexes causing their temperature-dependence
Energy-transfer mechanism in photoluminescent Terbium(III) complexes causing their temperature-dependence
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DOI：
10.1246/bcsj.80.1492
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发表时间：
2007-08-15
影响因子：
4
通讯作者：
Wada, Yuji
中科院分区：
文献类型：
--
作者：
Katagiri, Shinya;Tsukahara, Yasunori;Wada, Yuji
研究了[Tb（bfa）（3）（H2O）（2）]配合物的光致发光随温度的变化（bfa：4，4，4-三氟-1-苯基-1，3-丁二酮），[Tb（hfa）（3）（H2O）（3）]（hfa：六氟乙酰丙酮）、[Tb（tfa）（3）（H2O）（2）]（tfa：三氟乙酰丙酮）、[Tb（acaC）（3）（H2O）（3）]（acac：乙酰丙酮）和[Tb（hfa）（3）（tppo）（2）]（tppo：三苯基氧化膦）。这些配合物被分为两类，具有不同的温度依赖性。由[Tb（bfa）（3）（H2O）（2）]、[Tb（tfa）（3）（H2O）（2）]和[Tb（acac）（3）（H2O）（3）]组成的第一组显示出由配体的激发三重态之间的能隙和铽（III）离子的发射能级确定的依赖性。与此相对，对于含有hfa作为配体的[Tb（hfa）3（H2O）（3）]和[Tb（hfa）（3）（tppo）（2）]，为了理解它们的依赖性，不仅考虑了能隙，而且还考虑了从配体到铽（III）离子的“正向能量转移”和从铽（III）离子到配体的“反向能量转移”的能垒。这些结果进行了讨论的基础上的配合物的重新取向伴随着正向和反向能量转移过程，使用DFT计算。
Photoluminescence of Terbium(III) complexes was investigated as a function of temperatures in the range of 80-280 K for [Tb(bfa)(3)(H2O)(2)] (bfa: 4,4,4-trifluoro-1-phenyl-1,3-butanedionato), [Tb(hfa)(3)(H2O)(3)] (hfa: hexafluoroacetylacetonato), [Tb(tfa)(3)(H2O)(2)] (tfa: trifluoroacetylacetonato), [Tb(acaC)(3)(H2O)(3)] (acac: acetylacetonato), and [Tb(hfa)(3)(tppo)(2)] (tppo: triphenylphosphine oxide). These complexes were classified into the two groups with different temperature-dependences. The first group consisting of [Tb(bfa)(3)(H2O)(2)], [Tb(tfa)(3)(H2O)(2)], and [Tb(acac)(3)(H2O)(3)] showed a dependence determined by the energy gap between the excited triplet state of the ligand and the emitting level of terbium(III) ion. In contrast, for [Tb(hfa)3(H2O)(3)] and [Tb(hfa)(3)(tppo)(2)] containing hfa as a ligand, not only the energy gap but also the energy barriers of the "Forward energy transfer" from the ligand to terbium(III) ion and "Back energy transfer" from terbium(III) ion to the ligand were taken into account for understanding their dependences. These results are discussed based on the re-orientation of the complexes accompanied by the forward and back energy transfer processes using DFT calculations.