Chirality is one of the most important intrinsic properties of (supra)molecules. In this study, we obtained enantiomeric metallo‐supramolecular octahedra without using any chiral sources. Such cages were self‐assembled by prochiral trispyridine ligand L based on a C3h truxene core and CuII salts. Crystallization of the cages with BF4− as counterions afforded racemate crystals; while crystallizations of cages with ClO4− and OTf− as counterions resulted in conglomerates with spontaneous resolution. Three types of chirality were observed in each cage, including planar chirality of the truxene core, axial chirality from the pyridyl and truxene moieties, and propeller chirality of the pyridyl‐CuII coordination sites. The cages reported here are among the largest discrete synthetic metallo‐supramolecules ever reported with chiral self‐sorting behavior. Remarkably, the chiral cages exhibited very slow racemization even at low concentrations, suggesting their high stability in solution.

Chirality is one of the most important intrinsic properties of (supra)molecules. In this study, we obtained enantiomeric metallo‐supramolecular octahedra without using any chiral sources. Such cages were self‐assembled by prochiral trispyridine ligand L based on a C3h truxene core and CuII salts. Crystallization of the cages with BF4− as counterions afforded racemate crystals; while crystallizations of cages with ClO4− and OTf− as counterions resulted in conglomerates with spontaneous resolution. Three types of chirality were observed in each cage, including planar chirality of the truxene core, axial chirality from the pyridyl and truxene moieties, and propeller chirality of the pyridyl‐CuII coordination sites. The cages reported here are among the largest discrete synthetic metallo‐supramolecules ever reported with chiral self‐sorting behavior. Remarkably, the chiral cages exhibited very slow racemization even at low concentrations, suggesting their high stability in solution.

Comprehensive SummaryMetallo‐supramolecular architectures that are constructed by coordination‐driven self‐assembly have received tremendous attention on account of their diverse yet molecular‐level precise structures and broad applications. Of particular, metal cations and counter anions are fundamentally important in terms of self‐assembly, characterization and property; however, their effects on the structural stabilities of metallo‐supramolecular architectures have seldom been investigated. To address this issue, herein, a series of octahedral metallo‐cages that are capable of tolerating with five metal cations (Pd2+, Cu2+, Ni2+, Co2+ and Zn2+), and five counter anions (ClO4–, OTf–, BF4–, NTf2– and NO3–) are constructed by the coordination‐driven self‐assembly of a well‐designed tritopic isoquinoline‐based ligand with corresponding metal salts. Structural stability studies show that metal cations and counter anions play a critical role in the stability of the resulting cages depending on their coordination abilities and stacking manners. This work provides deep insights in the ever‐diversifying field of metallo‐supramolecular chemistry, and will enable us to design more sophisticated assembled structure with desired function.

Luminescent probes have wide applications in biological system analysis and environmental science. Here, one novel luminescent dinuclear europium compound with a crown ether analogous ligand was synthesized through a solvent–thermal reaction. Through transformation, upon the addition of Al3+ ions to the N,N′-dimethyl formamide solution of the europium compound, the luminescent intensity of the characteristic emission of Eu3+ decreased, and a new emission peak appeared at 346 nm and increased rapidly. The luminescent investigation indicated that it could act as a highly sensitive and selective luminescent probe for Al3+ ions. Moreover, mass spectrometry and single-crystal X-ray diffraction confirmed the formation of a new more stable trinuclear aluminium compound during the sensing process.