Year: 2026
Type: article
Abstract: ABSTRACT Here we present a five‐step synthesis of two circular polarized light emitting donor–acceptor (D–A) [17]helicenes. The concise yet high‐yielding synthetic strategy was achieved by dedicated precursor design, with bond‐order control and substitution effects, for photocyclization. The structures and chiroptical properties of D–A [17]helicenes were comprehensively characterized by NMR, HRMS, UV–vis, CD, fluorescence and CPL spectroscopies, as well as single‐crystal X‐ray diffraction. By introducing D–A system into helicene scaffold, we demonstrate a nearly 10‐fold increase in fluorescence quantum yield compared to the unsubstituted [14]helicene, due to an enhanced fluorescence emission rate ( k f ). The emission wavelength can be tuned by introducing different functional groups. D–A [17]helicenes emitting circularly polarized light with a dissymmetry factor ( g lum ) of up to 1 × 10 −2 . DFT calculations reveal that D–A functionalization increases the oscillator strengths ( f ) thereby increasing k f . This highly efficient synthetic strategy not only facilitates the synthesis of the longest chiral helicene reported to date but also establishes design principles for developing chiral long helicenes with circularly polarized light emission.
Institutions: Westlake University, Zhejiang University
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: bronze
Award: G420930304
OpenAlex ID: W7127973259