New strategies for the design and synthesis of stable organic radicals without additives are highly desirable. Herein, we design a series of donor-acceptor structured triarylphosphines and disclose the fast color...

The synthesis of 4‐(trifluoromethyl)‐2,3‐dihydrothiazoles from α‐enolic dithioesters and imidoyl sulfoxonium ylides has been achieved under thermal conditions. This transformation is catalyst‐free, additive‐free, and operationally simple, and it proceeds via a formal insertion of alkenyl S−H generated in situ from dithioesters into ylides followed by an intramolecular annulation. This approach further expands the synthetic application of two versatile sulfur‐containing building blocks of fluorinated imidoyl sulfoxonium ylides and α‐enolic dithioesters.

Figure 4. Top: Normalized prompt and delayed (1 ms) PL spectra; middle: CPL spectra; bottom: g lum of a) as-prepared and b) treated PVA films with doped (R)-1 (w (R)-1 :w PVA = 1 : 600) at room temperature with 290 nm excitation. Phosphorescent decay curves of c) as-prepared and d) treated PVA films with doped (R)-1 (w (R)-1 :w PVA = 1 : 600) at room temperature with 290 nm excitation. (inset: photographs of films under 254 nm excitation on and off).

The synthesis of aryl-fused 1,4-oxathiepines from pyridinium 1,4-zwitterionic thiolates with ortho-alkynyl aromatic phenols has been achieved in good to excellent yields under mild conditions. The key reactive intermediates (i.e., vinylidene...

Boosting the circularly polarized luminescence of small organic molecules has been a stubborn challenge because of weak structure rigidity and dynamic molecular motions. To investigate and eliminate these factors, here, we carried out the struc-ture-property relationship studies on a newly-developed axial chiral scaffold of bidibenzo[b,d]furan. The molecular rigidity was finely tuned by gradually reducing the alkyl-chain length. The environmental factors were considered in solution, crystal, and polymer matrix at different temperatures. As a result, a significant amplification of the dissymmetry factor glum from 10-4 to 10-1 with a 146-fold magnification was achieved, corresponding to the situation from (R)-4C in solution to (R)-1C in polymer film at room temperature. A synergistic strategy of increasing the intramolecular rigidity and enhancing the inter-molecular interaction to restrict the molecular motions was thus proposed to improve circularly polarized luminescence. The though-out demonstrated relationship will be of great importance for the development of high-performance small organic chiroptical systems in the future.