Related Experiment Video
Updated: Oct 26, 2026

Construction of Cyclic Cell-Penetrating Peptides for Enhanced Penetration of Biological Barriers
Published on: September 19, 2022
π-Extended D-A Type [5]Helicenes: Cyano-Based Construction and Enhanced CPL Performance
Chenxi Dong1, Shuai Qiu1, Wan Xu1
1Institute of Nanoscience and Engineering, Henan University, Kaifeng475004, China.
Abstract:
Two cyano-based D-A type [5]helicenes, N[5]Hs and P[5]Hs, were synthesized through key steps, including the Rosenmund-von Braun reaction, the Horner-Wadsworth-Emmons reaction, and elimination. Enhanced fluorescence emission is achieved with ΦFL reaching 39%; this enhancement is attributed to a strengthened intramolecular charge transfer (ICT) effect, which reduces the nonradiative rate (knr) in turn. The emission wavelength can be tuned by introducing different functional groups. Among them, P[5]HE3CN exhibited exceptional circularly polarized luminescence (CPL) properties, achieving a luminescence dissymmetry factor (|glum|) of up to 8.7 × 10-3. These results demonstrate that rational molecular design with a donor-acceptor framework can effectively modulate CPL performance parameters of materials such as glum and ΦFL.
Related Concept Videos
Structure of Conjugated Dienes
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
Long-patch Base Excision Repair
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Cable Subjected to Concentrated Loads
Conformations of Cyclohexane
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
