Highly emissive π-conjugated macrocycles with tunable circularly polarized luminescence (CPL) have sparked theoretical and synthetic interests in recent years. Herein, we report a synthetic approach to obtain new chiral organoborane macrocycles (CMC1, CMC2, and CMC3) that are built on the structurally chiral [5]­helicenes and highly luminescent triarylborane/amine moieties embedded into the cyclic systems. These rarely accessible B/N-doped main-group chiral macrocycles show a unique topology dependence of the optoelectronic and chiroptical properties. CMC1 and CMC2 show a higher luminescence dissymmetry factor (g lum) together with an enhanced CPL brightness (B CPL) as compared with CMC3. Electronic effects were also tuned and resulted in bathochromic shifts of their emission and CPL responses from blue for CMC1 to the near-infrared (NIR) region for CMC3. Furthermore, chemical oxidations of the N donor sites in CMC1 gave rise to a highly stable radical cation (CMC1 ·+ SbF 6 –) and diradical dication species (CMC1 2·2+ 2SbF 6 –) that serve as a rare example of a positively charged open-shell chiral macrocycle.

We herein present the synthetic approach to a new antiaromatic double aza[7]helicene C that features NN‐embedded polycyclic aromatic hydrocarbons (PAHs). This heteroatom‐doped helicene showed a rarely obtained long‐wavelength emission and far‐red circularly polarized luminescence (CPL) in the solid state. These optical and chiroptical properties could be ascribed to both the NN‐PAH core structure and the further extension through angular ring fusions. Such a unique electronic structure also culminated in facile chemical oxidations of neutral C to the positively charged chiral radical (C⋅+) and dication species (C2+). Interestingly, DFT computations revealed that the pyridazine central core showed an antiaromaticity‐to‐aromaticity switching, in contrast to the inversed transition for the helical periphery in cationic states. The reported approaches are anticipated to lead to the development of further redox‐active chiral systems for potential applications in chiroptoelectronics, spintronics as well as fluorescent bioimaging.

The employment of hydrogen-bond donors has become an important metal-free method for activating organic molecules considering their competency in epoxide activation and stabilization of reaction intermediates. In this work, pyridiniumbased ionic polymers (PIP) were synthesized, which readily reacted with 3,5-bis(trifluoromethyl)phenyl isothiocyanate and 3,5-bis-(trifluoromethyl) phenyl isocyanate under ambient conditions to introduce thiourea and urea structures into the porous polymer. Consequently, bifunctional polymers PIP-thiourea and PIP-urea containing quaternary ammonium centers and dual hydrogen-bond donors were fabricated. The polymers were tested as catalysts for the cycloaddition reaction of CO 2 and epoxides. The results reveal a higher catalytic activity of both catalysts PIP-thiourea and PIP-urea than that of catalyst PIP, which confirms the efficacy of the hydrogen bonds introduced by the post-modification in epoxide activation and catalytic activity improvement. A substantial yield of the corresponding cyclic carbonate products can be obtained with only 0.3 mol % catalysts. In addition, the as-synthesized heterogeneous catalysts exhibited good stability and excellent recyclability. Hopefully, the designed polymers will prove to play a powerful role in catalytic reactions for CO 2 utilization.