![THE INFLUENCE OF THE STRUCTURE OF 1H-IMIDAZO[4,5-F][1,10]PHENANTHROLINE DERIVATIVES ON THE LUMINESCENCE INTENSITY PARAMETERS OF EUROPIUM(III) COMPLEXES ACCORDING TO QUANTUM-CHEMICAL SIMULATION DATA](/upload/84d3a89c18d437fa8a9ddc6bbecb2e79/issues/cover/54112fd663ea6bd04835667de041d3de.jpeg)
THE INFLUENCE OF THE STRUCTURE OF 1H-IMIDAZO[4,5-F][1,10]PHENANTHROLINE DERIVATIVES ON THE LUMINESCENCE INTENSITY PARAMETERS OF EUROPIUM(III) COMPLEXES ACCORDING TO QUANTUM-CHEMICAL SIMULATION DATA
Rubrics: 1. CHEMISTRY
Authors:
1.
KNITU
2.
KNITU
Type:
Article
Pages:
from 48
to 52
Status:
Published
Received:
09.02.2026
Accepted:
16.03.2026
Published:
05.04.2026
Language:
Russian
Keywords:
EUROPIUM(III) COMPLEXES, QUANTUM-CHEMICAL CALCULATIONS, TRIPLET EXCITED STATES, INTRAMOLECULAR ENERGY TRANSFER, QUANTUM YIELD
Funding:
Rabota vypolnena za schet granta, predostavlennogo Akademiey nauk Respubliki Tatarstan obrazovatel'nym organizaciyam vysshego obrazovaniya, nauchnym i inym organizaciyam na podderzhku planov razvitiya kadrovogo potenciala v chasti stimulirovaniya ih nauchnyh i nauchno-pedagogicheskih rabotnikov k zaschite doktorskih dissertaciy i vypolneniyu nauchno-issledovatel'skih rabot (soglashenie №10/2025-PD-KNITU ot 22.12.2025).
Abstract:
Europium(III) complexes with β-diketones and Lewis bases are well-known molecular luminescent materials for optoelectronics, laser technologies, and sensor devices. They are characterized by narrow emission bands and long lifetimes of excited states. The molecular structure of the chromophoric ligand is a critical determinant for the efficiency of intramolecular excitation energy transfer to the europium(III) ion, thereby directly governing the resultant luminescence intensity of these complexes. In this article, quantum-chemical simulation methods were used to study the influence of the structure of some 1H-imidazo[4,5-f][1,10]phenanthroline derivatives on the luminescence intensity parameters of europium(III) complexes. Optimization of the molecular geometry of the complexes was performed using semiempirical methods. Additionally, calculations of the energies of triplet excited states were performed, which made it possible to estimate the probabilities of energy transfer from the ligands to the europium(III) ion. For each complex, spectroscopic characteristics were determined according to the Judd-Ofelt theory, including the parameters of luminescence intensity, energy transfer rates, and quantum yields. A comparative analysis of these parameters was carried out for complexes of various structures, differing in the nature of the substituents, their number, and the position in the 1H-imidazo[4,5-f][1,10]phenanthroline. Quantitative correlations between the structure of the ligands and the luminescence intensity were established, and promising compounds with effective luminescent properties were selected for the synthesis. The adequacy of the selected computational approaches and simulation data were confirmed by available experimental values. Thus, the effectiveness of quantum-chemical simulation as a tool for the directed molecular design of organic ligands was demonstrated, allowing for the prediction and targeted enhancement of the luminescent characteristics complexes of the rare earths before their experimental production.
Europium(III) complexes with β-diketones and Lewis bases are well-known molecular luminescent materials for optoelectronics, laser technologies, and sensor devices. They are characterized by narrow emission bands and long lifetimes of excited states. The molecular structure of the chromophoric ligand is a critical determinant for the efficiency of intramolecular excitation energy transfer to the europium(III) ion, thereby directly governing the resultant luminescence intensity of these complexes. In this article, quantum-chemical simulation methods were used to study the influence of the structure of some 1H-imidazo[4,5-f][1,10]phenanthroline derivatives on the luminescence intensity parameters of europium(III) complexes. Optimization of the molecular geometry of the complexes was performed using semiempirical methods. Additionally, calculations of the energies of triplet excited states were performed, which made it possible to estimate the probabilities of energy transfer from the ligands to the europium(III) ion. For each complex, spectroscopic characteristics were determined according to the Judd-Ofelt theory, including the parameters of luminescence intensity, energy transfer rates, and quantum yields. A comparative analysis of these parameters was carried out for complexes of various structures, differing in the nature of the substituents, their number, and the position in the 1H-imidazo[4,5-f][1,10]phenanthroline. Quantitative correlations between the structure of the ligands and the luminescence intensity were established, and promising compounds with effective luminescent properties were selected for the synthesis. The adequacy of the selected computational approaches and simulation data were confirmed by available experimental values. Thus, the effectiveness of quantum-chemical simulation as a tool for the directed molecular design of organic ligands was demonstrated, allowing for the prediction and targeted enhancement of the luminescent characteristics complexes of the rare earths before their experimental production.
Keywords:
EUROPIUM(III) COMPLEXES, QUANTUM-CHEMICAL CALCULATIONS, TRIPLET EXCITED STATES, INTRAMOLECULAR ENERGY TRANSFER, QUANTUM YIELD
EUROPIUM(III) COMPLEXES, QUANTUM-CHEMICAL CALCULATIONS, TRIPLET EXCITED STATES, INTRAMOLECULAR ENERGY TRANSFER, QUANTUM YIELD
