Crystal Structure Studies of Isopoly and Heteropoly Oxometalates. Structure of the Paradodecatungstate Molecule and Its Environment in Crystals

EvansJr., Howard T.

doi:10.1007/978-94-011-0920-8_6

Cited by 6 publications

(7 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The crystal structures of the recrystallized materials, established by single-crystal (section S1.1 of the Supporting Information) and powder XRD (Figure ), are in both cases consistent with the reported structures determined by neutron diffraction. , Importantly, both APT(H 2 O) 4 and APT(H 2 O) 10 are comprised of the same paratungstate B anion, [H 2 W 12 O 42 ] 10– , but differ in hydration sphere and therefore local symmetry, with the tetrahydrate APT(H 2 O) 4 crystallizing in the monoclinic P 2 1 / n space group and the decahydrate APT(H 2 O) 10 in the orthorhombic Pbca space group. Between the two crystal structures, W–O distances differ typically by <0.03 Å and average O–W–O angles are almost the same, though individual angles differ by ≤4°.…”

supporting

confidence: 79%

“…The crystal structures of the recrystallized materials, established by single-crystal (section S1.1 of the Supporting Information) and powder XRD (Figure 1), are in both cases consistent with the reported structures determined by neutron diffraction. 21,22 Given the near identical nature of the structures of the two anions, differences in their 183 W NMR spectra can be attributed primarily to differences in symmetry corresponding to the different locations of water and ammonium molecules in the crystal structures.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Solid-State ¹⁸³W NMR Spectroscopy as a High-Resolution Probe of Polyoxotungstate Structures and Dynamics

Berkson,

Bernhardt,

Copéret

2024

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

Polyoxometalates such as ammonium paratungstate (APT) constitute an important class of metal oxides with applications for catalysis, (opto)electronics, and functional materials. Structural analyses of solid polyoxometalates mostly rely on X-ray or neutron diffraction techniques, which are largely limited to compounds that can be isolated with long-range crystallographic order. While 183 W NMR has been shown to probe polyoxotungstate structures and dynamics in solution, its application to solids has been extremely limited. Here, state-of-the-art methods for the detection of solid-state 183 W NMR spectra are tested and compared for APT in different hydration states. The highly resolved solid-state spectra distinguish each crystallographically distinct site in the tungstate structure. Furthermore, the 183 W chemical shifts are shown to be highly sensitive to the local structure, dynamics, and symmetry of APT, establishing solid-state 183 W NMR spectroscopy as a potent probe for analysis of polyoxotungstates and other tungsten-derived materials to complement solution NMR and diffraction-based techniques.

show abstract

supporting

confidence: 79%

mentioning

confidence: 99%

Solid-State ¹⁸³W NMR Spectroscopy as a High-Resolution Probe of Polyoxotungstate Structures and Dynamics

Berkson,

Bernhardt,

Copéret

2024

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

show abstract

“…Even after thoroughly grinding the APT powder, it was not possible to obtain a powder average in the scattering signal of the APT precursor, as illustrated in Figure 5 A. The data show significant graininess and “spotty” X-ray diffraction patterns, but as shown in Figure S10 , ex situ measurements verify that the sample is pure APT with the crystal structure reported by Evans 63 containing the paratungstate B cluster.…”

Section: Resultsmentioning

confidence: 73%

“…Figure 6A shows the PDF obtained after 85 s fitted with the APT structure reported by Evans. 63 The calculated PDF peaks are slightly too sharp in the fit which is a common issue in crystals containing isolated molecules or ions, where the high r-peaks are broadened by intermolecular motions. 64,65 In the next frame, 90 s into the synthesis, a new phase appears, which can be identified as the cubic pyrochlore-type structure, WO 3 •0.5H 2 O.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of the Precursor Structure on the Formation of Tungsten Oxide Polymorphs

Juelsholt,

Aalling-Frederiksen,

Lindahl Christiansen

et al. 2023

Inorg. Chem.

View full text Add to dashboard Cite

Understanding material nucleation processes is crucial for the development of synthesis pathways for tailormade materials. However, we currently have little knowledge of the influence of the precursor solution structure on the formation pathway of materials. We here use in situ total scattering to show how the precursor solution structure influences which crystal structure is formed during the hydrothermal synthesis of tungsten oxides. We investigate the synthesis of tungsten oxide from the two polyoxometalate salts, ammonium metatungstate, and ammonium paratungstate. In both cases, a hexagonal ammonium tungsten bronze (NH4)0.25WO3 is formed as the final product. If the precursor solution contains metatungstate clusters, this phase forms directly in the hydrothermal synthesis. However, if the paratungstate B cluster is present at the time of crystallization, a metastable intermediate phase in the form of a pyrochlore-type tungsten oxide, WO3·0.5H2O, initially forms. The pyrochlore structure then undergoes a phase transformation into the tungsten bronze phase. Our studies thus experimentally show that the precursor cluster structure present at the moment of crystallization directly influences the formed crystalline phase and suggests that the precursor structure just prior to crystallization can be used as a tool for targeting specific crystalline phases of interest.

show abstract

In Situ Total X‐Ray Scattering Study of WO₃ Nanoparticle Formation under Hydrothermal Conditions

et al. 2014

View full text Add to dashboard Cite

Pair distribution function analysis of in situ total scattering data recorded during formation of WO3 nanocrystals under hydrothermal conditions reveal that a complex precursor structure exists in solution. The WO6 polyhedra of the precursor cluster undergo reorientation before forming the nanocrystal. This reorientation is the critical element in the formation of different hexagonal polymporphs of WO3.

show abstract

Crystal Structure Studies of Isopoly and Heteropoly Oxometalates. Structure of the Paradodecatungstate Molecule and Its Environment in Crystals

Cited by 6 publications

References 17 publications

Solid-State ¹⁸³W NMR Spectroscopy as a High-Resolution Probe of Polyoxotungstate Structures and Dynamics

Solid-State ¹⁸³W NMR Spectroscopy as a High-Resolution Probe of Polyoxotungstate Structures and Dynamics

Influence of the Precursor Structure on the Formation of Tungsten Oxide Polymorphs

In Situ Total X‐Ray Scattering Study of WO₃ Nanoparticle Formation under Hydrothermal Conditions

Contact Info

Product

Resources

About

Crystal Structure Studies of Isopoly and Heteropoly Oxometalates. Structure of the Paradodecatungstate Molecule and Its Environment in Crystals

Cited by 6 publications

References 17 publications

Solid-State 183W NMR Spectroscopy as a High-Resolution Probe of Polyoxotungstate Structures and Dynamics

Solid-State 183W NMR Spectroscopy as a High-Resolution Probe of Polyoxotungstate Structures and Dynamics

Influence of the Precursor Structure on the Formation of Tungsten Oxide Polymorphs

In Situ Total X‐Ray Scattering Study of WO3 Nanoparticle Formation under Hydrothermal Conditions

Contact Info

Product

Resources

About

Solid-State ¹⁸³W NMR Spectroscopy as a High-Resolution Probe of Polyoxotungstate Structures and Dynamics

Solid-State ¹⁸³W NMR Spectroscopy as a High-Resolution Probe of Polyoxotungstate Structures and Dynamics

In Situ Total X‐Ray Scattering Study of WO₃ Nanoparticle Formation under Hydrothermal Conditions