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An approach to preparing a functional fiber has been developed. The method is carried out to link nanometer-sized polyoxometalate and cotton fabric by employing a cationic agent. Interestingly, the composite fabric exhibits a broad absorption peak in the visible range after irradiation, accompanied by obvious color changes from white to blue owing to electron transfer. The W-(VI) transforms into a heteropoly blue W-(V) rapidly (<5 s) in response to UV irradiation with a low-power UV (5 W), whereas its recovery seems slightly slow (5 h) in the air. Nevertheless, increasing the temperature can accelerate the fading process. Further, the continuous coloring–fading process presents outstanding repetition stability. Additionally, the composite fabric shows a degree of antibacterial property. Meanwhile, the physical properties indicate that multifunctional cotton retains natural features after chemical modification. In a word, the reversible photoresponsive cellulose fabric can be a promising candidate for developing a wearable and flexible sensor to monitor environmental changes. [ABSTRACT FROM AUTHOR]

A new organic-inorganic hybrid heteropolyoxoniobate, [{Cu(en)(H 2 O) 4 }{Cu(en) 2 (H 2 O)}{Cu(en) 2 (H 2 O) 2 }] 1.5 [H 8 SiTe 8 Nb 15 O 64 ]·6H 2 O ( 1 ; en = ethanediamine), has been successfully synthesized by a conventional method. The compound was directed by pairs of [TeO 3 ] 2- /[SiO 3 ] 2- ions, generating two novel {TeNb 9 } and {SiTeNb 6 } subunits in situ owing to the mixed heteroanion. In addition, the solution behavior of compound 1 was investigated.

By adopting different crystal growth methods, two novel organic-inorganic hybrids, [{Cu(phen)} 6 (H 2 O)(Te 5 Nb 15.5 Cu 0.5 O 57 )] 3.5- and its dimer, have been successfully synthesized. These are fabricated by simple compound reactions and directed by the tellurite anions, which act as heteroanion templates and linkers, as well as a pendant ligand. The compounds were characterized by IR spectra, UV/vis, thermogravimetric analysis, and single crystal X-ray diffraction. Furthermore, the solution behavior was also investigated.

The first Co-containing polyoxotantalate cluster, [H 5 Co 8 Ta 24 O 80 ] 15- , has been obtained. The tetramer has by far the highest degree of polymerization of any polyoxotantalate based on {Ta 6 O 19 } and is the largest high-nuclearity Co-cluster-containing polyoxotantalate obtained thus far. The synthesis of new polyoxotantalates has long been a challenging subject in polyoxotantalate chemistry. The findings of this study show the possibility of using Ta-based polyoxometalates as ligands to construct large aggregated structures analogous to the related Nb compounds. Therefore, the work demonstrates exciting progress in the synthesis of new polyoxotantalates.

A novel 24-niobic-2-tellurite, [H 2 Te 2 Nb 24 O 72 ] 14- , was isolated by incorporating tellurite anions into a polyoxoniobate cage. The synthesized cluster represents the first example of a sandwich-type polyoxoniobate with the largest telluroniobate aggregate. Furthermore, the hybrid material acts as an efficient catalyst for the decolorization of basic fuchsin.

Polyoxometalates (POMs) of Nb and Ta are greatly different from those of Mo, W, and V that have been studied extensively and developed well. The latter can be formed simply by acidification of their aqueous monomeric oxoanions and has found application areas from catalysis to magnetism, materials science, medicine, and nanotechnology. Even now the polyoxoniobate (PONb) chemistry has accelerated dramatically over the last 15 years, and a vast expansion of available PONbs has been reported. However, after nearly 200 years of POM research, Ta-based POM chemistry is still at its infant stage and only dominated by the isopolyoxotantalate ions (Ta 6 and Ta 10 ) and transition-metal-capped Ta 6 species, along with two Ti-substituted polyoxotantalates [Ti 2 Ta 8 O 28 ] 8- and [Ti 12 Ta 6 O 44 ] 10- reported very recently. In this study, we discover two novel peroxotantalophosphate clusters [P 4 (TaO 2 ) 6 O 25 ] 12- (1) and [P 4 (TaO 2 ) 6 O 24 ] 10- (2) by incorporating phosphorus heteroatom into Ta-oxo framework, which represent the first two examples of heteropolytantalate. Interestingly, two P 2 Ta 3 half-units are cis- and trans-condensed in 1 and 2, leading to "open" and "closed" configurations, respectively. These two chemically and structurally related clusters can be isolated in a controlled manner, and the yields are relatively high. Both compounds were characterized in the solid state by single-crystal X-ray diffraction, 31 P MAS NMR, FT-IR, TGA, and elemental analysis as well as by 31 P NMR in solution. The results presented here provide a strategy to be applicable to other heteroatom-incorporated polyoxotantalates and further expand the phase space for polyoxotantalate chemistry.

A structurally intriguing polyanion, [{Nb4O6(OH)4}{Nb6P2W12O61}4](36-) (2), was directly formed by controlling the reaction parameters and characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analyses. Polyanion 2 is the first niobium-substituted Wells-Dawson-based tetramer and contains the largest Nb28 cluster encapsulated by four hexalacunary Wells-Dawson frameworks. The activities of compounds Na12[H24-2]·24H2O (2a), K12[H2P2W12O48]·24H2O, and K7[HNb6O19]·13H2O against three human tumor cell lines were investigated in vitro. The preliminary results revealed that 2a could efficiently inhibit the growth of the human breast cancer MCF-7 cells. Interestingly, the activity of 2a is significantly better than those of the simple reagents.