Effect of ancillary ligands on visible and NIR luminescence of Sm3+β-diketonate complexes

V S Sizov; D A Komissar; D A Metlina; D F Aminev; S A Ambrozevich; S E Nefedov; E A Varaksina; M T Metlin; V V Mislavskií; I V Taydakov

doi:10.1016/j.saa.2019.117503

Effect of ancillary ligands on visible and NIR luminescence of Sm³⁺β-diketonate complexes

Spectrochim Acta A Mol Biomol Spectrosc. 2020 Jan 15:225:117503. doi: 10.1016/j.saa.2019.117503. Epub 2019 Sep 7.

Authors

V S Sizov¹, D A Komissar², D A Metlina³, D F Aminev³, S A Ambrozevich⁴, S E Nefedov⁵, E A Varaksina⁶, M T Metlin⁷, V V Mislavskií⁸, I V Taydakov³

Affiliations

¹ 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. Electronic address: v_sizov@outlook.com.
² 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.
³ P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninsky Prospekt, Moscow 119991, Russian Federation.
⁴ 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; Bauman Moscow State Technical University, 5/1 2-ya Baumanskaya St., 105005 Moscow, Russian Federation.
⁵ Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, 31 Leninsky Prospekt, Moscow 119991, Russian Federation.
⁶ 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; A.N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences, 28 Vavilova St., Moscow 119991, Russian Federation.
⁷ 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.
⁸ Moscow Institute of Physics and Technology (State University), 9 Institutskiy per., Dolgoprudny 141700, Moscow Region, Russian Federation.

PMID: 31577985
DOI: 10.1016/j.saa.2019.117503

Abstract

Two new Sm³⁺ complexes with pyrazolic β-diketones bearing a CF₃ 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 Sm³⁺ 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 Sm³⁺ 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.

Keywords: Judd-Ofelt theory; Luminescence; Samarium; Sensitization efficiency; β -diketonate.