Luminescence properties of pyrazolic 1,3-diketone Ho3+ complex with 1,10-phenanthroline

D A Komissar; M T Metlin; S A Ambrozevich; I V Taydakov; A S Tobokhova; E A Varaksina; A S Selyukov

doi:10.1016/j.saa.2019.117229

Luminescence properties of pyrazolic 1,3-diketone Ho³⁺ complex with 1,10-phenanthroline

Spectrochim Acta A Mol Biomol Spectrosc. 2019 Nov 5:222:117229. doi: 10.1016/j.saa.2019.117229. Epub 2019 Jun 6.

Authors

D A Komissar¹, M T Metlin², S A Ambrozevich³, I V Taydakov⁴, A S Tobokhova⁴, E A Varaksina⁴, A S Selyukov⁴

Affiliations

¹ Moscow Institute of Physics and Technology (State University), 9 Institutskií per., 141700 Dolgoprudnyí, Moscow Region, Russia. Electronic address: komissar@phystech.edu.
² P. N. Lebedev Physics Institute of the Russian Academy of Sciences, 53 Leninskiy pr., 119991 Moscow, Russia; Bauman Moscow State Technical University, 5/1 2-ya Baumanskaya str., 105005 Moscow, Russia.
³ Moscow Institute of Physics and Technology (State University), 9 Institutskií per., 141700 Dolgoprudnyí, Moscow Region, Russia; P. N. Lebedev Physics Institute of the Russian Academy of Sciences, 53 Leninskiy pr., 119991 Moscow, Russia; Bauman Moscow State Technical University, 5/1 2-ya Baumanskaya str., 105005 Moscow, Russia.
⁴ Moscow Institute of Physics and Technology (State University), 9 Institutskií per., 141700 Dolgoprudnyí, Moscow Region, Russia; P. N. Lebedev Physics Institute of the Russian Academy of Sciences, 53 Leninskiy pr., 119991 Moscow, Russia.

PMID: 31202029
DOI: 10.1016/j.saa.2019.117229

Abstract

We performed spectroscopic investigations of a novel tris(1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)propane-1,3-dionato)(1,10-phenanthroline) holmium (III) complex. It was demonstrated that bonding the corresponding ligand environment to Ho³⁺ results in sensitization of the luminescence of the complex. The luminescence decay of the complex exhibits a biexponential behaviour. The short-lived component is attributed to the fluorescence of the ligand, whereas the long-lived component is connected with the Ho³⁺ emission. Using fluorescence lifetime imaging, it was shown that there is a single type of emission sites in the studied complex. Based on the results of the optical measurements, the energy diagram for the investigated Ho³⁺ complex was developed. It was shown that the energy transfer from the excited triplet level of the ligand environment to the ⁵F₅ level of Ho³⁺ is responsible for the emission of the ion in the complex.

Keywords: 1,10-Phenanthroline; 1,3-Diketones; Coordination compounds; Holmium; Luminescence; Pyrazole.