Helically Chiral NHC‐Gold(I) Complexes: Synthesis, Chiroptical Properties and Electronic Features of the [5]Helicene‐Imidazolylidene Ligand. Issue 34 (26th August 2021)

• Record Type: Journal Article
• Authors: Gauthier, Etienne S.; Cordier, Marie; Dorcet, Vincent; Vanthuyne, Nicolas; Favereau, Ludovic; Williams, J. A. Gareth; Crassous, Jeanne
• Is Part Of: European journal of organic chemistry. Issue 34(2021)
• Page Start: 4769
• Page End: 4776
• Publication Date: 2021-08-26
• Subjects: Carbene -- Circular dichroism -- CPL -- Gold(I) -- Helicene -- Organometallics; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.202100722
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: We describe the preparation of helically chiral gold(I) complexes bearing a [5]helicenic‐N‐heterocyclic carbene ligand. They were successfully obtained as enantiopure compounds by semi‐preparative chiral HPLC and their structural, chiroptical, and photophysical properties were subsequently investigated. Notably, strong electronic circular dichroism, dual emission from singlet and triplet states, with the timescale of the latter up to the millisecond range at room temperature, and moderate circularly phosphorescence were observed. The σ‐donating and π‐accepting properties of the constituent helical ortho ‐fused π‐conjugated carbene were investigated by classical quantitative analysis of the IR stretching frequencies and NMR characteristics of the corresponding Ir(CO)2 Cl complex and selenourea. Abstract : The golden twist : Monodentate [5]helicene‐imidazolylidene gold(I) complexes were prepared in good yields and structurally characterized. Benefiting from the presence of the configurationally stable [5]helicenic unit, they exhibit appealing chiroptical features, such as strong circular dichroism, moderate circularly polarized phosphorescence and dual emission with phosphorescence lifetimes up to the millisecond range.