Supramolecular Chemistry of Windmill-like Al10 Clusters: Adjustable Guests and Hydrogen-Bonding Networks for Enhanced Optical Limiting.

The interest in cluster chemistry lies not only in the development of new types of geometric structures but also in the higher-level connectivity and assembly of clusters at the supramolecular level. Here, we report a novel windmill-like Al10 cluster and consider this geometrically unique cluster as an anionic node assembled together with different cationic guests such as imidazolium and guanidinium. These guests with different hydrogen-bond angles can help to obtain a series of diverse hydrogen-bonding networks and then manipulate the stacking mode of hosts and guests. Furthermore, we realized a supramolecular approach to fine-tune the optical limiting properties of the cluster. This work not only enriches the host-guest chemistry of ionic windmill-like clusters but also opens up more possibilities for aluminum oxo cluster-based hydrogen-bonded frameworks.

Water-stable porous Al24 Archimedean solids for removal of trace iodine.

In this paper, we report a unique type of core-shell crystalline material that combines an inorganic zeolitic cage structure with a macrocyclic host arrangement and that can remove trace levels of iodine from water effectively. These unique assemblies are made up of an inorganic Archimedean truncatedhexahedron (tcu) polyhedron in the kernel which possesses six calixarene-like shell cavities. The cages have good adaptability to guests and can be assembled into a series of supramolecular structures in the crystalline state with different lattice pore shapes. Due to the unique core-shell porous structures, the compounds are not only stable in organic solvents but also in water. The characteristics of the cages enable rapid iodine capture from low concentration aqueous I2/KI solutions (down to 4 ppm concentration). We have studied the detailed process and mechanism of iodine capture and aggregation at the molecular level. The facile synthesis, considerable adsorption capacity, recyclability, and ß- and γ-radiation resistance of the cages should make these materials suitable for the extraction of iodine from aqueous effluent streams (most obviously, radioactive iodide produced by atomic power generation).