Search

The first enantiopure chiral‐at‐rhenium complexes of the form fac‐ReX(CO)3(:C^N) have been prepared, where :C^N is a helicene‐N‐heterocyclic carbene (NHC) ligand and X=Cl or I. These have complexes show strong changes in the emission characteristics, notably strongly enhanced phosphorescence lifetimes (reaching 0.7 ms) and increased circularly polarized emission (CPL) activity, as compared to their parent chiral models lacking the helicene unit. The halogen along with its position within the dissymmetric stereochemical environment strongly affect the photophysics of the complexes, particularly the phosphorescence quantum yield and lifetime. These results give fresh insight into fine tuning of photophysical and chiroptical properties of Re‐NHC systems. [ABSTRACT FROM AUTHOR]

The first enantiopure chiral‐at‐rhenium complexes of the form fac‐ReX(CO)3(:C^N) have been prepared, where :C^N is a helicene‐N‐heterocyclic carbene (NHC) ligand and X=Cl or I. These have complexes show strong changes in the emission characteristics, notably strongly enhanced phosphorescence lifetimes (reaching 0.7 ms) and increased circularly polarized emission (CPL) activity, as compared to their parent chiral models lacking the helicene unit. The halogen along with its position within the dissymmetric stereochemical environment strongly affect the photophysics of the complexes, particularly the phosphorescence quantum yield and lifetime. These results give fresh insight into fine tuning of photophysical and chiroptical properties of Re‐NHC systems. [ABSTRACT FROM AUTHOR]

A fused π-helical N-heterocyclic carbene (NHC) system was prepared and examined through its diastereoisomerically pure cycloiridiated complexes. The latter display light-green phosphorescence with unusually long lifetimes and circular polarization that depends on both the helical NHC P/ M stereochemistry and the iridium Δ/Λ stereochemistry. These unprecedented features are attributed to extended π conjugation within the helical carbenic ligand and efficient helicene-NHC-Ir interaction. [ABSTRACT FROM AUTHOR]

A fused π-helical N-heterocyclic carbene (NHC) system was prepared and examined through its diastereoisomerically pure cycloiridiated complexes. The latter display light-green phosphorescence with unusually long lifetimes and circular polarization that depends on both the helical NHC P/ M stereochemistry and the iridium Δ/Λ stereochemistry. These unprecedented features are attributed to extended π conjugation within the helical carbenic ligand and efficient helicene-NHC-Ir interaction. [ABSTRACT FROM AUTHOR]

The first helicene–NHC–iridium complexes have been prepared in enantiopure forms. Their stereochemical, electronic, and chiroptical features were characterized experimentally and via first-principles calculations, highlighting the helical and iridium-centered chirality. [ABSTRACT FROM AUTHOR]

Frontispiz: Long-Lived Circularly Polarized Phosphorescence in Helicene-NHC Rhenium(I) Complexes: The Influence of Helicene, Halogen, and Stereochemistry on Emission Properties Keywords: circularly polarized emission; helicenes; N-heterocyclic carbenes; phosphorescence; rhenium(I) EN circularly polarized emission helicenes N-heterocyclic carbenes phosphorescence rhenium(I) 1 1 1 05/18/20 20200525 NES 200525 B Chiroptische Verbindungen b In ihrer Zuschrift auf S. 8472 beschreiben J. A. G. Williams, J. Autschbach, J. Crassous et al. die Synthese von Rhenium(I)/NHC-Helicen-Komplexen mit zirkular polarisierter Phosphoreszenz sowie photophysikalische Untersuchungen dieser Verbindungen. Circularly polarized emission, helicenes, N-heterocyclic carbenes, phosphorescence, rhenium(I). [Extracted from the article]

Innentitelbild: Long-Lived Circularly Polarized Phosphorescence in Helicene-NHC Rhenium(I) Complexes: The Influence of Helicene, Halogen, and Stereochemistry on Emission Properties (Angew. Keywords: circularly polarized emission; helicenes; N-heterocyclic carbenes; phosphorescence; rhenium(I) EN circularly polarized emission helicenes N-heterocyclic carbenes phosphorescence rhenium(I) 8382 8382 1 05/18/20 20200525 NES 200525 B Zeitaufgelöste impulsive b stimulierte Raman-Spektroskopie, eine ultraschnelle Raman-Technik, ermöglicht es, Momentaufnahmen von Molekülen im angeregten Zustand mit hoher Empfindlichkeit und Zeitauflösung zu gewinnen. Circularly polarized emission, helicenes, N-heterocyclic carbenes, phosphorescence, rhenium(I). [Extracted from the article]