Triskelion-shaped iridium-helicene NHC complex

Etienne S. Gauthier (1) , Nora Hellou (1) , Elsa Caytan (1) , Samuel del Fré (2) , Vincent Dorcet (1) , Nicolas Vanthuyne (3) , Ludovic Favereau (1) , Monika Srebro-Hooper (2) , J. A. Gareth Williams (4) , Jeanne Crassous (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 UJ - Uniwersytet Jagielloński w Krakowie = Jagiellonian University
3 ISM2 - Institut des Sciences Moléculaires de Marseille
4 Durham University

Enantiopure tris-helicenic chiral-at-iridium complexes have been prepared, constituting the first examples of organometallic metal-tris-helicenes. They have the mer- or fac-Ir(C<^>C:)(3) form, where (C<^>C:) is an N-heterocyclic carbene ligand N-substituted with a hexahelicene. Their triskelion geometry and stereochemistry have been thoroughly studied and assigned by NMR in combination with quantum-chemical modelling and by comparison with the X-ray structure of analogues. Thanks to their Ir(iii)-based multihelicenic architecture, the complexes display strong electronic circular dichroism and optical rotation along with long-lived yellow phosphorescence, involving circularly polarized emission with g(lum) factors around 10(-3).

Domaines: Chimie de coordination

Etienne S. Gauthier, Nora Hellou, Elsa Caytan, Samuel del Fré, Vincent Dorcet, et al.. Triskelion-shaped iridium-helicene NHC complex. Inorganic Chemistry Frontiers, 2021, 8 (16), pp.3916-3925. ⟨10.1039/d1qi00527h⟩. ⟨hal-03331038⟩