Herein, a giant Sb-rich polyoxometalate (POM) {Sb 21 Tb 7 W 56 } is reported, which contains the largest number of Sb atoms in a POM so far. The Sbrich POM has many interesting structural features and is a rare example of a soluble and water-stable giant POM. Biomedical studies indicate that the Sb-rich POM exhibits broad-spectrum antitumor activity against various cancer cell lines by reactivating the P53-dependent apoptotic processes and disrupting the mitochondrial membrane. In addition, this Sb-rich POM was capable of suppressing the growth and metastasis of a breast cancer in vivo. This work demonstrates that Sb-rich POMs are promising candidates for the development of new anticancer drugs.Cancer remains the most malignant disease worldwide with high morbidity and mortality. [1] Although the development of therapeutic modalities has never stopped, chemotherapy remains one of the most prevalent therapeutic regimens. To date, chemotherapeutics based on organic, inorganic and hybrid species have been developed. [2] However, chemotherapeutics cause severe adverse effects including multiple organ failures and myelosuppression. [3] Thus, the exploration of new anticancer drugs with higher potencies and lower systemic toxicities remains challenging and requires longterm research.Polyoxometalates (POMs) have shown promising applications in various fields due to their unique structural features and rich physical and chemical properties, e.g. oxorich surface, tunable acid-base and redox properties. [4,5] These intriguing features also endow POMs with versatile bioactivities in the combat against viruses, bacteria and tumors. [6] Antimony, one heavy pnictogen, has been medicinally used for over 100 years. [7] Due to the stereo activity of the lone electron-pair, Sb-complexes can target protein tyrosine phosphatases and increase the generation of reactive oxygen species, leading to the apoptosis of cancer cells. [8] Recently, the introduction of Sb ions into POMs creating Sb-containing POMs has attracted increasing attention, because such composite POMs synergize the advantages of POMs and Sb, and thus become promising antitumor agents. [9] For example, {Co 4 Sb 9 W 24 }, [10] {Na 0.7 M 5.3 Sb 2 W 18 } (M = Ni/Co), [11] and {SbW 8 O 30 } [12] are reported to exhibit excellent antitumor activities. However, it is noteworthy that the known antitumor Sb-containing POMs are small-tomedium nuclearity (< 50) POMs with only a few Sb atoms (� 9, Table S1), and the incorporated Sb atoms in those POMs usually serve as heteroatoms wrapped by W/Mo shells, [13] which might hinder the contact with cancer cells thus impairing the antitumor activities of Sb. So, it is of great scientific interest to investigate whether increasing the nuclearity number of Sb atoms in a POM would improve the bioactivity against cancers. However, such studies remain largely unexplored due to the lack of Sb-rich POMs.Here, a rare and giant (> 2 nm) soluble Sb-rich POM H 27 [Sb 15 Tb 7 W 3 O 29 (OH) 3 (DMF)(H 2 O) 6 (SbW 8 O 30 )(SbW 9 O 33 ) 5 ]• 30 H 2 O ...

The assembly of heterometallic cluster substituted polyoxometalates (POMs) remains a great challenge for inorganic synthetic chemistry up to now. Herein, a series of 5p–4f heterometallic cluster substituted POMs were successfully isolated by a facile one-step hydrothermal reaction method, namely H17(H2en)3[SbIII 9SbVLn3O14(H2O)3]­[(SbW9O33)3(PW9O34)]·28H2O­(1-Ln, Ln = Ce, Sm, Eu, Gd, Tb, Dy) (en = ethylenediamine). Interestingly, by replacing en with imidazole, another series of 5p–4f heterometallic cluster substituted POMs H13(HIm)4K2Na4(H2O)9[SbIII 9SbVLn3O14(H2O)3]­[(SbW9O33)3(PW9O34)]·26H2O (2-Ln, Ln = Sm, Eu, Gd, Tb, Dy, Im = imidazole) were obtained. Structural analyses indicate that both 1-Ln and 2-Ln are made up of an unprecedented 5p–4f heterometallic {Sb10Ln3O14(H2O)3} cluster stabilized simultaneously by mixed trilacunary heteropolyanions including {A-α-PW9O34} and {B-α-SbW9O33}. Impedance measurements indicate that both compounds exhibit different proton conduction properties, and the conductivity of 2 can reach up to 1.64 × 10–2 S cm–1 at 85 °C under 98% relative humidity. Moreover, the fluorescence emission behaviors of both compounds have been studied.

Polyoxotantalates (POTas), as an important branch of polyoxometalates (POMs), remain largely undeveloped compared with other members of the POM family including polyoxovanadates, polyoxotungstates, polyoxomolybdates and polyoxoniobates. Over the past decades, searching for feasible strategies to develop new POTas has attracted continuous interest due to their promising applications in fields of photo/electrocatalysis, ion-conduction, environmental protection, magnetism, and so on. In this review, the development of POTas is summarized, including their synthetic methods, crystal structures, physicochemical properties, and potential applications. Additionally, synthetic challenges and prospects for POTas are also discussed. It is hoped that this review will be of reference value for the further development of POTas.

Two novel inorganic-organic hybrid 3-D TM-Ln incorporated POM-based frameworks, H2[Cu2OL3(H2O)2][Ce(L)(H2O)3(PW11O39)]·17H2O (1) and H4[CuL3]2[Ln(H2O)3(PW11O39)]2·28H2O (2), (L = 4,4'-bipyridine) were hydrothermally synthesized at different temperatures. Structural analysis reveals that both compounds are...

Herein, a giant Sb-rich polyoxometalate (POM) {Sb 21 Tb 7 W 56 } is reported, which contains the largest number of Sb atoms in a POM so far. The Sbrich POM has many interesting structural features and is a rare example of a soluble and water-stable giant POM. Biomedical studies indicate that the Sb-rich POM exhibits broad-spectrum antitumor activity against various cancer cell lines by reactivating the P53-dependent apoptotic processes and disrupting the mitochondrial membrane. In addition, this Sb-rich POM was capable of suppressing the growth and metastasis of a breast cancer in vivo. This work demonstrates that Sb-rich POMs are promising candidates for the development of new anticancer drugs.Cancer remains the most malignant disease worldwide with high morbidity and mortality. [1] Although the development of therapeutic modalities has never stopped, chemotherapy remains one of the most prevalent therapeutic regimens. To date, chemotherapeutics based on organic, inorganic and hybrid species have been developed. [2] However, chemotherapeutics cause severe adverse effects including multiple organ failures and myelosuppression. [3] Thus, the exploration of new anticancer drugs with higher potencies and lower systemic toxicities remains challenging and requires longterm research.Polyoxometalates (POMs) have shown promising applications in various fields due to their unique structural features and rich physical and chemical properties, e.g. oxorich surface, tunable acid-base and redox properties. [4,5] These intriguing features also endow POMs with versatile bioactivities in the combat against viruses, bacteria and tumors. [6] Antimony, one heavy pnictogen, has been medicinally used for over 100 years. [7] Due to the stereo activity of the lone electron-pair, Sb-complexes can target protein tyrosine phosphatases and increase the generation of reactive oxygen species, leading to the apoptosis of cancer cells. [8] Recently, the introduction of Sb ions into POMs creating Sb-containing POMs has attracted increasing attention, because such composite POMs synergize the advantages of POMs and Sb, and thus become promising antitumor agents. [9] For example, {Co 4 Sb 9 W 24 }, [10] {Na 0.7 M 5.3 Sb 2 W 18 } (M = Ni/Co), [11] and {SbW 8 O 30 } [12] are reported to exhibit excellent antitumor activities. However, it is noteworthy that the known antitumor Sb-containing POMs are small-tomedium nuclearity (< 50) POMs with only a few Sb atoms (� 9, Table S1), and the incorporated Sb atoms in those POMs usually serve as heteroatoms wrapped by W/Mo shells, [13] which might hinder the contact with cancer cells thus impairing the antitumor activities of Sb. So, it is of great scientific interest to investigate whether increasing the nuclearity number of Sb atoms in a POM would improve the bioactivity against cancers. However, such studies remain largely unexplored due to the lack of Sb-rich POMs.Here, a rare and giant (> 2 nm) soluble Sb-rich POM H 27 [Sb 15 Tb 7 W 3 O 29 (OH) 3 (DMF)(H 2 O) 6 (SbW 8 O 30 )(SbW 9 O 33 ) 5 ]• 30 H 2 O ...