Transferable Semiempirical Models for Judd-Ofelt Parameters and Multiphonon Relaxation in Eu³⁺ Complexes: Toward an...

Area of Science:

• Materials Science
• Theoretical Chemistry
• Luminescence

Background:

• Designing lanthanide-based luminescent systems theoretically is challenging due to reliance on experimental data.
• Existing models often require extensive experimental validation for accurate predictions.

Purpose of the Study:

• To develop a theoretical protocol for designing new Europium(III) (Eu³⁺) based luminescent systems.
• To enable rational design starting from a single experimentally characterized complex.

Main Methods:

• Utilized a combination of the QDC and BOM models to calculate Judd-Ofelt intensity parameters (Ω₂, Ω₄).
• Employed a model based on the van Dijk-Schuurmans equation and Fermi's golden rule to estimate nonradiative emission rates (A_NR).
• Parameterized and validated models using experimentally characterized Eu³⁺ complexes.

Main Results:

• The protocol accurately reproduced Judd-Ofelt parameters with average errors below 4%.
• Nonradiative rates were predicted with high accuracy (errors below 0.2%).
• Predicted quantum yields for methoxy-substituted complexes reached ~93.8%, indicating superior performance.

Conclusions:

• The developed theoretical protocol offers a computationally efficient strategy for designing Eu³⁺ luminescent materials.
• The approach successfully predicts luminescent properties, guiding the discovery of high-performance materials.
• Methoxy-substituted bipyridine ligands show promise for enhanced Eu³⁺ luminescence.