Chiral Emissive Lanthanide Complexes from Enantiopure [6]Helicene-bis(pyrazolyl)-pyridine Ligands

Alexandre Abherve (1, 2, 3) , Maurizio Mastropasqua Talamo (1, 2, 3) , Nicolas Vanthuyne (4) , Francesco Zinna (5) , Lorenzo Di Bari (5) , Maxime Grasser (6) , Boris Le Guennic (6) , N. Avarvari (1, 2, 3)

1 UA - Université d'Angers
2 MOLTECH-Anjou
3 MATRIX - SFR UA MATéRIauX
4 ISM2 - Institut des Sciences Moléculaires de Marseille
5 University of Pisa - Università di Pisa
6 ISCR - Institut des Sciences Chimiques de Rennes

Enantiopure helicene-based bis(pyrazol-1-yl)pyridine (bpp-[6]helicene), with the helicene unit in position 4 of the pyridine ring, have been prepared and structurally characterized. Their chiroptical properties have been studied experimentally, and both absorption and circular dichroism (CD) spectra have been reproduced theoretically by time-dependent density functional theory (TDDFT). Remarkably, in spite of the remote localization of the helicene with respect to the coordination pocket of the bpp motif, chiral Eu(III) complexes based on these ligands show, however, circularly polarized luminescence in the visible region, sustained by TDDFT and CASSCF calculations, which also emphasize the possible antenna effect of the bpp ligand.

Mots clés: Circular dichroism; Circularly polarized luminescence; Helicenes; Lanthanide complexes; N ligands

Domaines: Chimie; Chimie inorganique

Alexandre Abherve, Maurizio Mastropasqua Talamo, Nicolas Vanthuyne, Francesco Zinna, Lorenzo Di Bari, et al.. Chiral Emissive Lanthanide Complexes from Enantiopure [6]Helicene-bis(pyrazolyl)-pyridine Ligands. European Journal of Inorganic Chemistry, 2022, 2022 (11), pp.e202200010. ⟨10.1002/ejic.202200010⟩. ⟨hal-03629851⟩