The exploration of high nuclearity molecular metal oxide clusters and their reactivity is a challenge for chemistry and materials science. Herein, we report an unprecedented giant molecular cerium-bismuth tungstate superstructure formed by self-assembly from simple metal oxide precursors in aqueous solution. The compound, {[W Ce O ]([W Bi Ce (H O) O ][B-α-BiW O ] ) } was identified by single-crystal X-ray diffraction and features 104 metal centers, a relative molar mass of ca. 24 000 and is ca. 3.0×2.0×1.7 nm in size. The cluster anion is assembled around a central {Ce } octahedron which is stabilized by several molecular metal oxide shells. Six trilacunary Keggin anions ([B-α-BiW O ] ) cap the superstructure and limit its growth. In the crystal lattice, water-filled channels with diameters of ca. 0.5 nm are observed, and electrochemical impedance spectroscopy shows pronounced proton conductivity even at low temperature.

The hierarchical aggregation of molecular nanostructures from multiple components is a grand synthetic challenge, which requires highly selective linkage control. We demonstrate how two orthogonal linkage groups, that is, organotin and lanthanide cations, can be used to drive the aggregation of a giant molecular metal oxide superstructure. The title compound {[(Sn(CH 3 ) 2 ) 2 O] 4 {[CeW 5 O 18 ] [TeW 4 O 16 ]-[CeSn(CH 3 ) 2 ] 4 [TeW 8 O 31 ] 4 } 2 } 46À (1 a) features dimensions of ca. 2.2 2.3 3.4 nm 3 and a molecular weight of ca. 25 kDa. Structural analysis shows the hierarchical aggregation from several independent subunits. Initial biomedical tests show that 1 features an inhibitory effect on the proliferation of HeLa cells based on an apoptosis pathway. In vivo experiments in mice reveal the antiproliferative activity of 1 and open new paths for further development of this new compound class.

A family of unprecedented tellurotungstate-based organotin-rare-earth (RE) heterometallic hybrids [HN(CH)]HNa {[Sn(CH)WO(IN)][(B-α-TeWO)RE(HO) (Ac)]}·25HO [RE = Ce (1), Pr (2), Nd (3), Sm (4), Eu (5), Gd (6), Tb (7); HIN = isonicotinic acid, HAc = acetic acid] were synthesized and characterized by elemental analyses, IR spectra, UV spectra, thermogravimetric analyses, powder X-ray diffraction, and single-crystal X-ray diffraction. The polyoxoanionic skeletons {[Sn(CH)WO(IN)][(B-α-TeWO)RE(HO) (Ac)]} of 1-7 are constructed from two symmetrical units {[Sn(CH)WO(IN)][(B-α-TeWO)RE(HO) (Ac)]} linked by two acetate connectors, which not only represent the first inorganic-organic hybrid RE-substituted tellurotungstates involving three different organic ligands, but also stand for the first samples of organotin-RE heterometallic polyoxometalate derivatives. The solid-state luminescent emission properties of 2-5 mainly display the characteristic emission bands of RE cations, whereas during the emission procedure of 7, [B-α-TeWO] segments make a nonignorable contribution to the PL behavior of 7 accompanying by the occurrence of the intramolecular energy transfer from O→W LMCT energy to Tb centers. Furthermore, 4@CTAB composites with peanutlike and honeycombed morphologies were prepared by a surfactant cetyltrimethylammonium bromide (CTAB). The time-resolved emission spectra of the 4@CTAB composite with CTAB/4 = 0.033/0.05 consolidate the energy transfer from CTAB to RE centers. Variable-temperature magnetic susceptibility measurements for 2, 3, and 4 were performed.