De-Xian Wang

Supramolecular radical cages are captivating architectures in supramolecular chemistry and materials science; however, their construction and precise regulation of electronic states and magnetic properties remain substantially challenging. Herein, we report the synthesis, structures, and magnetic properties of a series of covalent organic radical cages, generated by reducing the benzene triimide (BTI) radical precursors within the corresponding neutral cages. The m ‐xylene‐bridged cage with two parallel BTI units separated by 5.4 Å undergoes stepwise reduction to afford both mixed‐valence monoradical and diradical cages. In contrast, the cavity‐expanded cage with naphthalene bridges (7.6 Å) preferentially gives a mixed‐valence monoradical even under excess reductant. This discrepancy originates from cavity‐mediated host–guest interactions of the radical cages, which selectively stabilize the mixed‐valence monoradical of the naphthalene‐bridged cage. All the radical cages exhibit good stability and are characterized by single‐crystal x‐ray diffraction, EPR, and UV–vis–NIR spectroscopy. For the m ‐xylene‐bridged diradical cage, the two BTI radical units are weakly coupled, exhibiting a singlet ground state with a narrow singlet–triplet energy gap (Δ E _ST = –1.63 kcal/mol). The naphthalene‐bridged mixed‐valence monoradical cage features an unpaired electron delocalized over the two BTI units and exhibits antiferromagnetic interactions arising from its one‐dimensional linear assembly in the solid state.

Supramolecular radical cages are captivating architectures in supramolecular chemistry and materials science; however, their construction and precise regulation of electronic states and magnetic properties remain substantially challenging. Herein, we report the synthesis, structures, and magnetic properties of a series of covalent organic radical cages, generated by reducing the benzene triimide (BTI) radical precursors within the corresponding neutral cages. The m ‐xylene‐bridged cage with two parallel BTI units separated by 5.4 Å undergoes stepwise reduction to afford both mixed‐valence monoradical and diradical cages. In contrast, the cavity‐expanded cage with naphthalene bridges (7.6 Å) preferentially gives a mixed‐valence monoradical even under excess reductant. This discrepancy originates from cavity‐mediated host–guest interactions of the radical cages, which selectively stabilize the mixed‐valence monoradical of the naphthalene‐bridged cage. All the radical cages exhibit good stability and are characterized by single‐crystal x‐ray diffraction, EPR, and UV–vis–NIR spectroscopy. For the m ‐xylene‐bridged diradical cage, the two BTI radical units are weakly coupled, exhibiting a singlet ground state with a narrow singlet–triplet energy gap (Δ E _ST = –1.63 kcal/mol). The naphthalene‐bridged mixed‐valence monoradical cage features an unpaired electron delocalized over the two BTI units and exhibits antiferromagnetic interactions arising from its one‐dimensional linear assembly in the solid state.

Cation–chloride cotransporters (CCCs) are an important family of chloride channel proteins that mediate electroneutral transport of Cl ⁻ with Na ⁺ and/or K ⁺ . In this study, we introduced ultracycles (molecular shakers—so named for their cocktail‐shaker‐like shape) designed to mimic the binding sites and functions of KCC1. These ultracycles incorporate both anion (S _Cl1 , S _Cl2 ) and cation (S _K ) binding sites within the single‐molecular backbone. The synthesis was achieved through dynamic nucleophilic aromatic substitution, starting from a rigid‐flexible macrocyclic precursor and diphenol derivatives. Planar lipid bilayer measurements demonstrated that the molecular shakers function as single‐molecule channels, mediating ion transport. By varying the structural features of the lower and larger rims of the macrocycle, as well as the glycol chains and the pH of the bulk solution, we achieved a permeability ratio up to P _Cl ⁻ / P _K ⁺ = 0.83.

Cation–chloride cotransporters (CCCs) are an important family of chloride channel proteins that mediate electroneutral transport of Cl ⁻ with Na ⁺ and/or K ⁺ . In this study, we introduced ultracycles (molecular shakers—so named for their cocktail‐shaker‐like shape) designed to mimic the binding sites and functions of KCC1. These ultracycles incorporate both anion (S _Cl1 , S _Cl2 ) and cation (S _K ) binding sites within the single‐molecular backbone. The synthesis was achieved through dynamic nucleophilic aromatic substitution, starting from a rigid‐flexible macrocyclic precursor and diphenol derivatives. Planar lipid bilayer measurements demonstrated that the molecular shakers function as single‐molecule channels, mediating ion transport. By varying the structural features of the lower and larger rims of the macrocycle, as well as the glycol chains and the pH of the bulk solution, we achieved a permeability ratio up to P _Cl ⁻ / P _K ⁺ = 0.83.

Understanding and exploiting noncovalent interactions are essential for advancing chemical transformations and catalysis. While both cation–π and anion–π interactions have attracted growing attention, their deliberate use as a dominant design element remains elusive. Here, we present an ion–π catalysis strategy employing both π interactions as the key driving force to steer challenging stereoselective carbocation transformation, enabling catalytic enantioconvergent S _N 1 reactions. Through straightforward one‐pot synthesis, we efficiently constructed a series of chiral cages composed solely of aromatic units, featuring electron‐rich asymmetric π clefts and electron‐deficient π exterior surfaces. This all‐π system leverages strong cation–π interactions to trap and stabilize carbocation intermediates within its chiral V‐cleft, while simultaneously engaging the counteranion via anion–π interactions on its exterior surface. This synergistic π network drives a highly enantioconvergent S _N 1 process, enabling asymmetric allylation of propargyl acetates to form congested quaternary stereocenters. This system shows considerable sensitivity to subtle electronic and steric changes, resembling enzymatic behavior. This work provides a strategic approach for harnessing noncovalent π interactions to address challenging transformations.

Understanding and exploiting noncovalent interactions are essential for advancing chemical transformations and catalysis. While both cation–π and anion–π interactions have attracted growing attention, their deliberate use as a dominant design element remains elusive. Here, we present an ion–π catalysis strategy employing both π interactions as the key driving force to steer challenging stereoselective carbocation transformation, enabling catalytic enantioconvergent S _N 1 reactions. Through straightforward one‐pot synthesis, we efficiently constructed a series of chiral cages composed solely of aromatic units, featuring electron‐rich asymmetric π clefts and electron‐deficient π exterior surfaces. This all‐π system leverages strong cation–π interactions to trap and stabilize carbocation intermediates within its chiral V‐cleft, while simultaneously engaging the counteranion via anion–π interactions on its exterior surface. This synergistic π network drives a highly enantioconvergent S _N 1 process, enabling asymmetric allylation of propargyl acetates to form congested quaternary stereocenters. This system shows considerable sensitivity to subtle electronic and steric changes, resembling enzymatic behavior. This work provides a strategic approach for harnessing noncovalent π interactions to address challenging transformations.

Herein, we report a strategy employing chiral macrocycles for the in situ trapping of catalytically active anions, enabling highly efficient and enantioselective catalysis. By exploiting the strong anion‐binding ability of tailored bis‐thiourea macrocycles, active peroxotungstate species generated from a Na ₂ WO ₄ /Na ₃ PO ₄ /H ₂ O ₂ system are selectively captured within a confined chiral cavity. Using only 1 mol% macrocycle, sulfide oxidation proceeds efficiently to afford sulfoxides in up to 95% yield and 91% ee. Mechanistic studies identify a macrocycle‐bound phosphato‐bis(oxoperoxotungstate) complex as the key catalytic species. The pronounced macrocyclic effect and the fine stereochemical modulation in response to subtle structural variations underscore the precise control conferred by the confined environment. This work demonstrates that macrocyclic anion trapping can steer the reactivity and stereoselectivity of otherwise elusive polyanionic catalysts—offering a distinct approach that operates beyond conventional cationic ion‐pairing systems. The strategy is expected to be applicable to a wide range of catalytic transformations involving active anionic species.

Zeolite Beta, one of the earliest recognized chiral zeolitic systems and widely used in the chemical industry, poses a significant challenge for characterizing its chiral structure because of its intergrowth of polymorphs. Herein, we report a comprehensive electron crystallography framework for the determination of polymorph ratios, absolute structures, and enantiomeric distributions in zeolite Beta. By developing an optimized real‐space imaging protocol based on scanning transmission electron microscopy, we circumvent the mechanical tilting limits of electron microscopy, enabling chiral identification even at arbitrary crystal orientations. Furthermore, we introduce a weighted refinement strategy for 3D electron diffraction (3D ED). By utilizing dynamical diffraction simulations to derive weighting factors from enantiomeric intensity disparities, the sensitivity of absolute structure determination is significantly enhanced, overcoming the dilution of chiral signals by centrosymmetric components. Experimental validation confirms that this integrated approach accurately quantifies regional polymorph A enrichment and successfully discriminates between P 4 ₁ 22 and P 4 ₃ 22 enantiomers. This work not only addresses long‐standing challenges in characterizing intergrown chiral zeolites but also provides a refined methodological paradigm for investigating such complex porous materials.

Novel and functional organic building blocks are essential resources for developing materials with unique structures and outstanding properties. Here, we designed ultracycles that contain oxacalix[2]arene[2]triazine as subunits and pentaethylene glycol chains as linkers. These ultracycles were synthesized through a one-pot reaction between rigid and flexible macrocyclic precursors and diphenol derivatives. Featuring multitopic binding sites in close proximity, the ultracycles extracted various ion pairs from solid to organic solvent under ¹H NMR monitoring, and the ion pair binding was confirmed quantitatively in solution. The crystal structures of [UC1-2CaBr₂] and [UC2-2LiClO₄] complexes indicate that cations are dominantly chelated by glycol chains through ion–dipole interaction, while anions are stabilized by cation–anion electrostatic attraction or anion–π interactions. The large size of the ultracycles and their unique ion-pair binding modes afford the crystals with a hierarchical framework with porous architecture, namely ion pair organic frameworks (IPOFs). This includes the largest central cavities of the ultracycles, the intrinsic cavities of the constituent sub-macrocycles, and the interspaces arising from molecular packing. These IPOFs, serving as sorbents, demonstrated highly efficient iodine vapor capture at room temperature and atmospheric pressure, with a maximum uptake amount of 1.81 mg/mg.

Chalcogen bond (ChB)–based heteroditopic receptors integrating neutral or positively charged thiazole motifs as anion binding sites and glycol chains as cation binding sites into a host framework were synthesized. ¹ H NMR titration experiments revealed that the neutral receptors showed stronger binding ability for cations than for anions, whereas the protonated receptors demonstrated significantly enhanced anion binding but largely diminished cation association. In solution, the charge–neutral receptors displayed ion‐pair binding due to the allosteric effect from the bound cation and anion. Single–crystal X–ray analysis demonstrated the ion pairs are stabilized by the thiazoles through ChB interactions, the glycol chain through ion–dipole interactions, and cation–anion interactions.