The Keggin structure, known as an archetypical polyoxometalate (POM) structural motif, has widened up our fundamental understanding of the growth behavior of natural metal oxide minerals. However, devising a strategy for synthesis of such species consisting of pure-metal ions remains a great challenge. Different from those sixcoordinated early transition metal ions in Keggin POMs, lanthanide prefers higher coordination numbers, making the construction of lanthanide-Keggin structure more difficult. Here, we report the unprecedented luminescent Keggin-type Eu 13 nanocluster constructed through a facile solvothermal method using the high-symmetry macrocyclic tetrasilane (Ph 4 Si 4 O 8 ) 4− as the capping ligand. This protocol demonstrates an important proof of concept for assembly of metallasilsesquioxanes. The structure shows a rare polyoxometalate-Eu-oxo-core@SiO 2 -shell@organicshell (Eu13) consisting of a central EuO 8 cube, surrounded by 12 edge-sharing EuO 7 monocapped trigonal prisms. It is the highestnuclearity lanthanide−silsesquioxane nanocluster. Electrospray ionization mass spectrometry reveals that Eu13 is stable in solution except for some labile terminal dimethylformamide on the ligand shell, which endows Eu13 with a high catalytic activity for CO 2 cycloaddition reaction with small epoxides under ambient conditions. Eu13 also exhibits intense red luminescence upon visible light excitation (466 and 535 nm). The photophysical and photoelectric properties of the drop-casting film of Eu13 indicate its great potential in optoelectric device applications.

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Impatiens walleriana (I. walleriana), a potential cadmium (Cd) hyperaccumulator, can propagate by cuttings, which are less expensive to grow than seedlings. Different growth periods for cuttings, however, may lead to different physiological characteristics. In this study, I. walleriana cuttings were hydroponically grown in Cd-containing solutions (1.0-10.0 μM) for various growth periods (10-60 days). Experimental results showed that the Cd treatments had negative effects on growth compared to the controls that were not spiked with Cd. The extension of the growth period promoted most of the growth exhibitions of I. walleriana, except for SPAD readings for cuttings grown in the 5.0 and 10.0 μM solutions. The accumulation of Cd also increased over time, except in the roots of the cuttings grown in the 5.0 and 10.0 μM solutions. The subcellular distribution and chemical forms of Cd showed that I. walleriana developed better tolerance and detoxification capacities in the cuttings grown in the 5.0 and 10.0 μM solutions than in the cuttings grown in the other two Cd treatments.