Easy separation of Δ and Λ isomers of highly luminescent [Ir(III)]-cyclometalated complexes based on chiral phenol-oxazoline ancillary ligands

Enrico Marchi; Riccardo Sinisi; Giacomo Bergamini; Michele Tragni; Magda Monari; Marco Bandini; Paola Ceroni

doi:10.1002/chem.201200709

Easy separation of Δ and Λ isomers of highly luminescent [Ir(III)]-cyclometalated complexes based on chiral phenol-oxazoline ancillary ligands

Chemistry. 2012 Jul 9;18(28):8765-73. doi: 10.1002/chem.201200709. Epub 2012 Jun 11.

Authors

Enrico Marchi¹, Riccardo Sinisi, Giacomo Bergamini, Michele Tragni, Magda Monari, Marco Bandini, Paola Ceroni

Affiliation

¹ Dipartimento di Chimica G. Ciamician, Alma Mater Studiorum, Università di Bologna via Selmi 2, 40126 Bologna 40126, Italy.

PMID: 22689328
DOI: 10.1002/chem.201200709

Abstract

A new class of neutral cyclometalated iridium(III) complexes with enantiomerically pure C(1)-symmetric phenol-oxazolines (3a,b) have been synthetized in high yields and fully characterized. Resolution of the corresponding Δ(R) and Λ(R) or Δ(S) and Λ(S) isomers was easily achieved by conventional flash chromatography. The corresponding Δ and Λ helicities have been confirmed by CD spectroscopy and X-ray crystallography. Regarding the absorption and luminescence properties with unpolarized light, no significant difference between Δ and Λ isomers has been observed. A strong blue luminescence is observed for deaerated solutions of complexes 5a and 5b in CH(3)CN.