Efficiency of the energy transfer through 5d state of the Ln3+ ion in complexes with diarylcyclopentadienyl ligands

Optical Materials. 2025. Vol. 160. Article 116734.

Puntus L., Varaksina E., Bardonov D., Minyaev M., Lyssenko K., Chernenkiy T., Taydakov I., Nifant'ev I., Roitershtein D.

Lanthanide tris complexes with unsubstituted and diarylcyclopentadienyl ligands have been synthesized and studied by single crystal X-ray diffraction analysis and optical spectroscopy. It is shown that the ligand field
formed by three Cp ligands can be an effective tool to decrease the energy of 4f5d configuration and as a result
for Ce complexes the luminescence in red region and energy of 5d1 level as 470 nm were observed. The energy
transfer scheme S → 4f5d → 4ff* realized in the designed complexes has been deciphered by the comparison of
the spectroscopic data for Ce3+, Pr3+, Gd3+ and Tb3+ ions. The spectroscopic redshift of the first electric dipole allowed 4f-5d transition of the Ce3+ ion was interpreted by combining the centroid shift and the crystal-field
splitting for organometallic compounds at the first time.

Keywords: перенос заряда, lanthanide, лантанид, charge transfer, cyclopentadienyl, циклопентадиенил, optical spectroscopy, оптическая спектроскопия