Pushkarev A P, Yablonskiy A N, Yunin P A, Burin M E, Andreev B A, Bochkarev M N
G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Tropinina 49, 603950 Nizhny Novgorod, Russian Federation.
Nizhny Novgorod State University, Gagarina avenue 23/2, 603950 Nizhny Novgorod, Russian Federation; Institute for Physics of Microstructures of Russian Academy of Sciences, 7 ul. Akademicheskaya, 603950 Nizhny Novgorod, Russian Federation.
Spectrochim Acta A Mol Biomol Spectrosc. 2016 Jun 15;163:134-9. doi: 10.1016/j.saa.2016.03.026. Epub 2016 Mar 25.
The samarium complexes Sm(S2PPh2)3(THF)2 (1) and Sm(Se2PPh2)3(THF)2 (2) with soft-donor dithia- and diselenophosphinate ligands were synthesized and their photophysical properties were studied in detail. Both complexes displayed the metal-centered photoluminescence (PL) in visible and NIR regions corresponding to (4)G5/2→(6)HJ (J=5/2, 7/2, 9/2, 11/2, 13/2, 15/2), (6)FJ (J=1/2, 3/2, 5/2, 7/2, 9/2, 11/2) f-f transitions of Sm(3+). Luminescence decay curves exhibit an initial short build-up region and can be described by double or triple exponential function owing to multiphonon relaxation from the (4)F3/2 energy level to the (4)G5/2 one and reversible energy transfer from the Sm(3+) excited states to the triplet ((3)T1) state of phosphinate ligand. A Judd-Ofelt analysis was performed to estimate PL quantum efficiency (QE), branching ratios (β) and induced-emission cross section (σem) of the compounds obtained. It was found that the Judd-Ofelt parameter Ω2 of 1 is significantly greater than that of 2. This feature is responsible for large values of β (50.98%) and σem (4.29×10(-21)cm(2)) which suggest 1 as a good candidate for the development of samarium doped polymethylmethacrylate (PMMA) laser medium acting on the (4)G5/2→(6)H9/2 transition at 645nm. The estimated room-temperature PL QE of 1 and 2 equals to 1.9 and 0.17%, respectively.
合成了带有软供体二硫代和二硒代次膦酸酯配体的钐配合物Sm(S2PPh2)3(THF)2（1）和Sm(Se2PPh2)3(THF)2（2），并详细研究了它们的光物理性质。两种配合物在可见光和近红外区域均表现出以金属为中心的光致发光（PL），对应于Sm(3+)的(4)G5/2→(6)HJ（J = 5/2、7/2、9/2、11/2、13/2、15/2）、(6)FJ（J = 1/2、3/2、5/2、7/2、9/2、11/2）f-f跃迁。发光衰减曲线呈现出初始的短上升区域，由于从(4)F3/2能级到(4)G5/2能级的多声子弛豫以及从Sm(3+)激发态到次膦酸酯配体的三重态((3)T1)态的可逆能量转移，可用双指数或三指数函数来描述。进行了Judd-Ofelt分析以估计所得化合物的PL量子效率（QE）、分支比（β）和诱导发射截面（σem）。发现1的Judd-Ofelt参数Ω2明显大于2的。这一特征导致β（50.98%）和σem（4.29×10(-21)cm(2)）的值较大，这表明1是开发用于645nm处(4)G5/2→(6)H9/2跃迁的钐掺杂聚甲基丙烯酸甲酯（PMMA）激光介质的良好候选物。估计1和2在室温下的PL QE分别为1.9%和0.17%。
