Dimerization of A-α-[SiNb3W9O40]7- by pH-Controlled Formation of Individual Nb−μ-O−Nb Linkages

Kim, Gyu-Shik; Zeng, Huadong; Neiwert, Wade A.; Cowan, Jennifer J.; VanDerveer, Donald G.; Hill, Craig L.; Weinstock, Ira A.

doi:10.1021/ic0341845

Cited by 51 publications

(33 citation statements)

References 38 publications

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“…Ionic strength was varied by additions of NaCl, and reported ionic-strength values include contributions from the Keggin ion salts. pD values of D 2 O solutions were calculated using pD = pH el + 0.4, where pH el values are readings from standard pH electrodes immersed in the D 2 O solutions [14,15].…”

Section: Aqueous Electrolyte Solutionsmentioning

confidence: 99%

Ionic-strength dependence of electron-transfer reactions of Keggin heteropolytungstates: Mechanistic probes of O2 activation in water

Geletii

Weinstock

2006

Journal of Molecular Catalysis A: Chemical

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Section: Aqueous Electrolyte Solutionsmentioning

confidence: 99%

Ionic-strength dependence of electron-transfer reactions of Keggin heteropolytungstates: Mechanistic probes of O2 activation in water

Geletii

Weinstock

2006

Journal of Molecular Catalysis A: Chemical

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“…If the solution of the reactants were left to heat at 90 °C for less than 2 h, we have been unable to isolate single crystals of compound 1 , however, it was found that there was no obvious increase in the yields when the heating time was more than 4 h. In addition, the reaction is not particularly sensitive to the amount of Eu III because 1 could be obtained with the mole ratios of Eu III /Nb 6 ranging from 6:1 to 16:1, with 10:1 giving the highest yield. It is worth mentioning here that compounds 1 − 8 can be isolated without the need for extra cations, different from an essential templating role of Cs + in the formation of Keggin and Wells-Dawson-type niobium-substituted polyoxotungstates 28–31, 41–43 .…”

Section: Resultsmentioning

confidence: 99%

“…Nevertheless, most of the reported TM-containing PONb derivatives are synthesized by hydrothermal or hydrothermal-diffusion methods. In contrast, some Nb-substituted polyoxotungstates of the classic Lindqvist or Keggin derivatives has been produced under acidic solution in the presence of H 2 O 2 28–31 . Recently, we have successfully manipulated the reaction of Nb 6 cluster under acidic condition by an in-situ synthetic strategy 19–22 .…”

Section: Introductionmentioning

confidence: 99%

Synthesis, structure, and luminescent properties of a family of lanthanide-functionalized peroxoniobiophosphates

Wang

Sun

et al. 2017

Sci Rep

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Eight new lanthanide derivatives containing 6-peroxoniobio-4-phosphate building block, [LnIII(H2O)6]2[H4(NbO2)6P4O24]·nH2O [Ln = Eu (1), Gd (2), Tb (3), Dy (4), Ho (5), Er (6), Tm (7), Yb (8), 1–5, 7, 8 n = 12; 6 n = 9], have been successfully obtained using an in-situ strategy and fully characterized in the solid state by single-crystal X-ray diffraction, IR spectra, TG-MS, PXRD. Structural analyses indicate that these isostructural polyanions 1–8 consist of one [P4(NbO2)6O24]10− (P 4 (NbO 2 ) 6) clusters and two pendant Ln3+ cations. In these compounds, P 4(NbO 2 ) 6 clusters are connected by lanthanide cations to form extended two-dimensional architectures. The approach takes advantage of the ability of in-situ formed P 4(NbO 2 ) 6 cluster to build frameworks by using it as ligands to lanthanide ions. The photoluminescence (PL) and lifetime decay behaviors of 1, 3 and 4 in solid state have been performed at room temperature. The PL emission of 1, 3 and 4 is mainly derived from the characteristic 5D0→7FJ (J = 1, 2, 3, 4), 5D4→7FJ (J = 6, 5, 4, 3) and 4F9/2→6H J (J = 15/2, 13/2, 11/2) transitions of the EuIII, TbIII and DyIII cations, respectively.

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“…Materials Cs 6 H[Si(NbO 2 ) 3 W 9 O 37 ]·8 H 2 O was synthesized according to the procedure described in the literature, [10] and the powder product was used without further purification. The material was characterized by IR spectroscopy and elemental analysis.…”

Section: Methodsmentioning

confidence: 99%

“…Moreover, these clusters are soluble in water and could be viewed as the smallest nanoparticles with ordered structures at the atomic level. [10] We propose that by sandwiching of transition-metal cations, visible-light-active photocatalysts may be achieved. [5] During the past few years, the photocatalytic H 2 evolution activity of polyoxotungstates has been studied.…”

mentioning

confidence: 99%

Self‐Assembly and Visible‐Light Photocatalytic Properties of W/Nb Mixed‐Addendum Polyoxometalate and Transition‐Metal Cations

et al. 2013

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Nowadays, energy issues are one of the most pressing problems faced by human beings. The conversion of solar energy into hydrogen as a clean and renewable fuel is a promising and attractive approach. Since Fujishima and Honda first reported photoinduced water splitting on titanium dioxide electrodes under UV irradiation in 1972, [1] large numbers of metal oxides and sulfides have been explored as heterogeneous photocatalysts for hydrogen production from splitting of water. [2] In this field, although significant progress has been made as hundreds of photocatalysts have been prepared and tested, great effort is needed to search for photocatalysts with high enough efficiencies and visible-light activity for practical applications. [3] Polyoxometalates (POMs) are an outstanding class of inorganic metal oxide clusters with abundant structural diversity and versatile physical and chemical properties that have potential applications in catalysis, electrical conductivity, photochemistry, medicine, and magnetism. [4] Similar to metal oxide semiconductors (such as TiO 2 , titanates, Ta 2 O 5 , and tantalates), POMs are mostly constructed from corner-and edge-shared MO 6 (M = Mo 6 + , W 6 + , V 5 + , Nb 5 + , Ta 5 + ) octahedra. The similarities in composition and structure endow POMs and metal oxide semiconductors with similar electronic and light-absorption characteristics in the photocatalytic system. Moreover, these clusters are soluble in water and could be viewed as the smallest nanoparticles with ordered structures at the atomic level. Therefore, besides the advantage of extra-large surface area allowing for full contact of photocatalysts with water, POMs provide an ideal opportunity to study the relationship between photocatalytic activity and inorganic cluster structures. [5] During the past few years, the photocatalytic H 2 evolution activity of polyoxotungstates has been studied. [6] However, the development of polyoxoniobate photocatalysts is still in its in-fancy, [7] and the reported polyoxoniobates are mostly active under UV irradiation. [8] Therefore, it is of great interest to develop novel polyoxoniobate photocatalysts with visible-light activity for more efficient use of solar energy. To achieve visiblelight H 2 evolution activity, the only solution is to increase the valence-band position of the photocatalysts. One effective strategy to achieve this is to dope transition-metal cations (Ni 2 + , Cr 3 + ) or to introduce main-group cations into the metal oxide photocatalysts to increase the valence-band position by hybridization of O 2p with d or s orbitals of metal cations. [5a, 9]

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Dimerization of A-α-[SiNb₃W₉O₄₀]^7- by pH-Controlled Formation of Individual Nb−μ-O−Nb Linkages

Cited by 51 publications

References 38 publications

Ionic-strength dependence of electron-transfer reactions of Keggin heteropolytungstates: Mechanistic probes of O2 activation in water

Ionic-strength dependence of electron-transfer reactions of Keggin heteropolytungstates: Mechanistic probes of O2 activation in water

Synthesis, structure, and luminescent properties of a family of lanthanide-functionalized peroxoniobiophosphates

Self‐Assembly and Visible‐Light Photocatalytic Properties of W/Nb Mixed‐Addendum Polyoxometalate and Transition‐Metal Cations

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