P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninsky Prospekt, Moscow 119991, Russian Federation; Bauman Moscow State Technical University, 5/1 2-ya Baumanskaya St., 105005 Moscow, Russian Federation.
P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninsky Prospekt, Moscow 119991, Russian Federation; Moscow Institute of Physics and Technology (State University), 9 Institutskiy per., Dolgoprudny 141700, Moscow Region, Russian Federation.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Jan 15;225:117503. doi: 10.1016/j.saa.2019.117503. Epub 2019 Sep 7.
Two new Sm complexes with pyrazolic β-diketones bearing a CF group acting as main ligands and with 2,2'-bipyridine or 1,10-phenanthroline being the ancillary ligand were studied, and their energy level structure was established. Stark splitting observed in the photoluminescence spectra of the complexes points to their non-cubic symmetry, confirmed by the calculated Judd-Ofelt intensity parameters. Internal quantum yields obtained for the compounds by the Judd-Ofelt calculations were of the order of 5.5%, whereas the measured external quantum yields were 0.75% and 1.5% for Sm complexes involving 2,2'-bipyridine and 1,10-phenanthroline ancillary ligands, respectively, with the corresponding sensitization efficiencies calculated as 0.16 and 0.26. It was demonstrated that replacing the 1,10-phenanthroline ancillary ligand with 2,2'-bipyridine provides an increase in the intensity of 650 nm emission of the Sm complexes, with the branching ratio reaching 55%. Intensive emission of the studied complexes at 650 nm offers hope for their use as spectrally pure red emitters.
研究了两种新型 Sm 配合物，它们以带有 CF 基团的吡唑啉酮β-二酮作为主要配体，以 2,2'-联吡啶或 1,10-菲啰啉作为辅助配体。建立了它们的能级结构。配合物光致发光光谱中观察到的斯塔克分裂表明其非立方对称性，这通过计算的 Judd-Ofelt 强度参数得到证实。通过 Judd-Ofelt 计算获得的化合物的内量子产率约为 5.5%，而对于涉及 2,2'-联吡啶和 1,10-菲啰啉辅助配体的 Sm 配合物，测量的外量子产率分别为 0.75%和 1.5%，相应的敏化效率计算为 0.16 和 0.26。结果表明，用 2,2'-联吡啶代替 1,10-菲啰啉辅助配体可提高 Sm 配合物在 650nm 处的发射强度，分支比达到 55%。研究的配合物在 650nm 处的强烈发射为它们用作光谱纯红色发射器提供了希望。
