Novel actinide cluster fullerenes, U2C2@I h (7)-C80 and U2C2@D 3h (5)-C78, were synthesized and fully characterized by mass spectrometry, single-crystal X-ray crystallography, UV–vis–NIR, nuclear magnetic resonance spectroscopy (NMR), X-ray absorption spectroscopy (XAS), Raman spectroscopy, IR spectroscopy, as well as density functional and multireference wave function calculations. The encapsulated U2C2 is the first example of a uranium carbide cluster featuring two U centers bridged by a CC unit. The U–C bond distances in these U2C2 clusters are in the range between 2.130 and 2.421 Å. While the U2C2 cluster in U2C2@C80 adopts a butterfly-shaped geometry with a U–C2–U dihedral angle of 112.7° and a U–U distance of 3.855 Å, the U–U distance in U2C2@C78 is 4.164 Å and the resulting U–C2–U dihedral angle is increased to 149.1°. The combined experimental and quantum-chemical results suggest that the formal U oxidation state is +4 in the U2C2 cluster, and each U center transfers three electrons to the C2n cage and one electron to C2. Different from the strong UC covalent bonding reported for U2C@C80, the U–C bonds in U2C2 are less covalent and predominantly ionic. The C–C triple bond is somewhat weaker than in HCCH, and the C–C π bonds undergo donation bonding with the U centers. This work demonstrates that the combination of the unique encapsulation effect of fullerene cages and the variable oxidation states of actinide elements can lead to the stabilization of novel actinide clusters, which are not accessible by conventional synthetic methods.

Metal chalcogenide supertetrahedral Tn clusters are of current interest for their unique compositions and structures, which rely highly on the structure-directing agents. Herein, we report four novel Tn cluster-based indium and gallium sulfides, namely, [NH(CH 3 ) 3 ] 4 In 4 S 10 H 4 (1), (NH 3 ) 4 Ga 4 S 6 (2), [NH 3 CH 2 CH 3 ] 5 (NH 2 CH 2 CH 3 ) 2 Ga 11 S 19 (3), and [NH 3 CH 2 -CH 2 OH] 6 Ga 10 S 18 •2NH 2 CH 2 CH 2 OH ( 4). All four compounds were solvothermally synthesized in mixed amine−ethanol solutions or deep eutectic solvent (DES), where ammonia/amine molecules play significant structure-directing roles in the speciation and crystal growth. (1) Being protonated, the trimethylamine and ethanolamine molecules surround the T2-[In 4 S 10 H 4 ] 4− clusters (for 1) and [Ga 10 S 18 ] n 6n− open framework (for 4), respectively, compensating for the negative charge of the inorganic moieties. (2) With the lone pair of electrons, the ammonia molecules in 2 coordinate directly to corner Ga 3+ ions of the {Ga 4 S 6 } cage to give a neutral T2-(NH 3 ) 4 Ga 4 S 6 cluster. (3) For compound 3, part of the ethylamine molecules act as terminating ligands for the T1 and T3 units in the [Ga 11 S 19 (NH 2 CH 2 CH 3 ) 2 ] n 5n− layer, while the rest act as interlamellar countercations upon protonation. Theoretical studies reveal the contributions of N, C, and H to the density of states (DOS) for 2 and 3 because of their hybrid structures that combine the ammonia/amine ligands with sulfide moieties together.

An ethylammonium-templated indium sulfide, [CH 3 CH 2 NH 3 ] 6 In 8 S 15 (InS-2), featuring anionic layers perforated with large, 24-membered rings that facilitate the accommodation of hydrated Sr 2+ ions is reported. InS-2 exhibits an excellent adsorption performance toward Sr 2+ with a top-ranked capacity (q m = 143.29 mg g −1 ), rapid kinetics, wide pH durability (3−14), βand γ-radiation resistances, and a facile elution.

Switchable coadsorption and separation for elimination/partitioning of Cs + and Sr 2+ is achieved by pH-controlled ion exchange using a potassium thioantimonate K 2 Sb 4 S 7 •2H 2 O (SbS-1K) with fantastic pH durability from diluted NaOH (pH 12) to concentrated HCl (3 m). At pH 6, SbS-1K exhibits ultrafast adsorption kinetics (R ≈ 90% in 2 min for Cs + and 20 min for Sr 2+ ) and high removal rates (R ≈ 98-99%) at equilibrium for both Cs + and Sr 2+ . At pH 2, the Sr 2+ adsorption is inhibited by H + with a great loss in R Sr to 11.18%, whereas the R Cs remains at 96.99%, contributing to a top-ranked separation factor SF Cs/Sr of 256. The SbS-1K-filled ion exchange column can be switched between the eliminating (R Cs > 99.91%; R Sr > 98.19%) and separating (R Cs > 98.99%; R Sr ≈ 0±3%) modes for treating continuous flow with a variation from pH 6 to pH 2 or vice versa. The SbS-1K/PTFE membrane exhibits coadsorption and separation effects for filtration of low concentrated mixed Cs + and Sr 2+ solution (1 ppm for each), even at an ultrafast vacuum filtration speed (30 mL min -1 ). Combined with easy synthesis and high β/γ irradiation resistance, SbS-1K represents a new-concept bifunctional exchanger with discriminating intelligence for equipment innovation.

Visualization of the ion exchange mechanism for 137Cs and 90Sr decontamination bears significance for safe radioactive liquid waste reprocessing and emergency response enhancement to nuclear accident. Here, the remediation of...