Here, we report the synthesis of two new sets of dibismuthbridged rare earth molecules. The first series contains a bridging diamagnetic Bi 2 2− anion, (Cp* 2 RE) 2 (μ-η 2 :η 2 -Bi 2 ), 1-RE (where Cp* = pentamethylcyclopentadienyl; RE = Gd (1-Gd), Tb (1-Tb), Dy (1-Dy), Y (1-Y)), while the second series comprises the first Bi 2 3− radical-containing complexes for any d- cryptand), which were obtained from one-electron reduction of 1-RE with KC 8 . The Bi 2 3− radical-bridged terbium and dysprosium congeners, 2-Tb and 2-Dy, are single-molecule magnets with magnetic hysteresis. We investigate the nature of the unprecedented lanthanide−bismuth and bismuth−bismuth bonding and their roles in magnetic communication between paramagnetic metal centers, through single-crystal X-ray diffraction, ultraviolet−visible/ near-infrared (UV−vis/NIR) spectroscopy, SQUID magnetometry, DFT and multiconfigurational ab initio calculations. We find a π z * ground SOMO for Bi 2 3− , which has isotropic spin−spin exchange coupling with neighboring metal ions of ca. −20 cm −1 ; however, the exchange coupling is strongly augmented by orbitally dependent terms in the anisotropic cases of 2-Tb and 2-Dy. As the first examples of p-block radicals beneath the second row bridging any metal ions, these studies have important ramifications for single-molecule magnetism, main group element, rare earth metal, and coordination chemistry at large.

Due to the trade-off barrier between high storage capacity and high selectivity, the controllable and systematic design of metal–organic frameworks (MOFs) aiming at performance optimization is still challenging. Herein, considering the effectiveness of alkoxy group functionalization and a pore-space partition strategy, a series of rigid Mg-pacs-MOFs (SNNU-10-n , n = 1–6) with flexible side chains are built for the first time, realizing systematic pore environmental modification. The steric hindrance effects, electron-donating ability, and the flexibility of alkoxy groups are considered as key factors, which lead to a regular change of gas adsorption capacity and selectivity. Notably, methoxy-modified SNNU-10-1 with moderately high storage capacities of C2H2 (139.4 cm3 g–1), C2H4 (100.4 cm3 g–1), CO2 (105.0 cm3 g–1), and high selectivity values for equimolar C2H2/CH4 (431.8), C2H4/CH4 (164.2), and CO2/CH4 (16.1) mixture separation at 273 K and 100 kPa achieves an ideal gas uptake-selectivity balance. Breakthrough experiments verified that it could effectively separate the above-mentioned mixtures under ambient conditions, and GCMC simulation provides a deep understanding of methoxy group functionalization. Undoubtedly, this work not only realizes controllable regulation of gas adsorption behavior but also proves the validity of improving selectivity by alkoxy groups in those platforms with high gas-uptake potential to overcome the trade-off barrier.

Homochiral metal−organic macrocyclic complexes are of great significance owing to their chirality and well-defined internal cavities that potentially have the ability to mimic complicated biological processes. Here we report a novel metal/anioncoordination co-driven strategy for the formation of nanoscale supramolecular metallocycles with unique topology, large size, and desired chirality. The enantiomeric Janus-type metallocyclic strips are assembled based on the synergistic coordination of sulfate anions and Co II ions to a bifunctional achiral ligand combining the o-phenylene-(bis)urea anion-chelating and 8-hydroxyquinoline metal-coordinating sites. The inherent chirality arises from two types of helical chiralities (triply twisted Mobius ring and circular helicate), which is observed for the first time for metal−organic complex systems. Notably, spontaneous chiral resolution by conglomerate crystallization into a pair of enantiomers (P-or M-Co 9 ) is realized, which is attributed to the multiple weak intermolecular interactions facilitating the hierarchically helical superstructure.

The selective separation of C2H2 from C2H2/CO2 and C2H2/C2H4 is crucial but remains incredibly challenging due to their extremely similar physical characteristics and nearly equivalent molecular kinetic diameters. Here, four novel pillared-layer-like metal–organic frameworks (MOFs) with quadrilateral channels, SNNU-283–286, which consist of a unique two-dimensional wave layer and carboxylic acid ligands as columns, are successfully synthesized via a facile solvothermal process. Interestingly, with the decrease of the bent angle between two −COOH groups in ligands, the distortion of the quadrilateral channel increases, and the two-dimensional wave layer becomes more curving. The optimized SNNU-285 with appropriate structural distortion exhibits remarkably high C2H2 adsorption capacity (124.6 cm3 g–1), superior selectivity (20.2), and enhanced breakthrough interval times (21.6 min g–1 at 273 K) for C2H2/CO2 due to the exposed open metal site and the polar furan ring. This work offers novel pillared-layer-like MOFs with quadrilateral channels for efficient C2H2 adsorption and purification.

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