TY  - JOUR
A1  - Full, Felix
A1  - Wölflick, Quentin
A1  - Radacki, Krzysztof
A1  - Braunschweig, Holger
A1  - Nowak‐Król, Agnieszka
T1  - Enhanced Optical Properties of Azaborole Helicenes by Lateral and Helical Extension
T2  - Chemistry – A European Journal
N2  - The synthesis and characterization of laterally extended azabora[5]‐, ‐[6]‐ and ‐[7]helicenes, assembled from N‐heteroaromatic and dibenzo[g,p]chrysene building blocks is described. Formally, the π‐conjugated systems of the pristine azaborole helicenes were enlarged with a phenanthrene unit leading to compounds with large Stokes shifts, significantly enhanced luminescence quantum yields (Φ) and dissymmetry factors (g\(_{lum}\)). The beneficial effect on optical properties was also observed for helical elongation. The combined contributions of lateral and helical extensions resulted in a compound showing green emission with Φ of 0.31 and |g\(_{lum}\)| of 2.2×10\(^{−3}\), highest within the series of π‐extended azaborahelicenes and superior to emission intensity and chiroptical response of its non‐extended congener. This study shows that helical and lateral extensions of π‐conjugated systems are viable strategies to improve features of azaborole helicenes. In addition, single crystal X‐ray analysis of configurationally stable [6]‐ and ‐[7]helicenes was used to provide insight into their packing arrangements.
KW  - azaborole
KW  - circularly polarized luminescence
KW  - fluorescence
KW  - helicene
KW  - π-extension
Y1  - 2022
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/29367
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-293671
VL  - 28
IS  - 62
ER  -