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

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 222; p. 117229
• Main Authors: Komissar, D.A., Metlin, M.T., Ambrozevich, S.A., Taydakov, I.V., Tobokhova, A.S., Varaksina, E.A., Selyukov, A.S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.11.2019
• Subjects: 1,10-Phenanthroline; 1,3-Diketones; Coordination compounds; Holmium; Luminescence; Pyrazole; 1,10-Phenanthroline; 1,3-Diketones; Coordination compounds; Holmium; Pyrazole; Luminescence
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2019.117229

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. [Display omitted] •A novel Ho3+ complex with 1,3-diketonate ligands is designed.•Ho3+-centered luminescence involving the “antenna” effect is demonstrated.•The energy diagram for the Ho3+ complex is developed.•A single type of emission sites in the complex is discovered.