Mixed-addenda vanadium-substituted polyfluorooxometalates

Synthesis, characterization, and catalytic aerobic oxidation

Alexander M. Khenkin, Ronny Neumann

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

For the first time, mixed-addenda vanadium-substituted polyfluorooxometalates, PFOMs, have been synthesized. Depending on the workup procedure used, two types of compounds were prepared. The first PFOM was a quasi Wells-Dawson type compound, [H2F6NaV(V)W17O56]8-, and the second a mixture of vanadium-substituted polyfluorooxometalates of the Keggin structure, XV(IV)W11F(n)O(40-n) (X = H2, V, W; n = 1-4). From the X-ray diffraction analysis, [H2F6NaV(V)W17O56]8- has an elliptic (egg) shape with a central sodium atom surrounded by six fluorine atoms in a trigonal prism coordination. One may differentiate between two types of addenda atoms to be found in belt and capped positions. According to 1H, 19F, and 51V NMR analysis, it is concluded that vanadium is isomorphically substituted in both the belt and capped position of [H2F6NaV(V)W17O56]8-. The mixture of vanadium-substituted PFOMs of the Keggin structure was shown, by HPLC and ESR, to contain at least two species of different charge and of a different vanadium environment. The [H2F6NaV(V)W17O56]8- PFOM was active for the catalytic aerobic oxidation of alkyl aromatic compounds in biphasic (water-catalyst and substrate) media. The reaction selectivity (autoxidation versus oxydehydrogenation) depended on the substrate and reaction conditions such as temperature and oxygen pressure. The selectivity to oxydehydrogenation was significantly higher compared to the prototypical cobalt acetate catalytic system.

Original languageEnglish
Pages (from-to)3455-3462
Number of pages8
JournalInorganic Chemistry
Volume39
Issue number16
DOIs
Publication statusPublished - Aug 7 2000

Fingerprint

Vanadium
vanadium
Oxidation
oxidation
synthesis
Atoms
cobalt acetates
selectivity
atoms
Fluorine
Catalyst selectivity
aromatic compounds
Aromatic compounds
eggs
Substrates
Prisms
Cobalt
X ray diffraction analysis
prisms
Paramagnetic resonance

ASJC Scopus subject areas

  • Inorganic Chemistry

Cite this

Mixed-addenda vanadium-substituted polyfluorooxometalates : Synthesis, characterization, and catalytic aerobic oxidation. / Khenkin, Alexander M.; Neumann, Ronny.

In: Inorganic Chemistry, Vol. 39, No. 16, 07.08.2000, p. 3455-3462.

Research output: Contribution to journalArticle

@article{0c8a592bd74e4b7696b7b67ff16c10ae,
title = "Mixed-addenda vanadium-substituted polyfluorooxometalates: Synthesis, characterization, and catalytic aerobic oxidation",
abstract = "For the first time, mixed-addenda vanadium-substituted polyfluorooxometalates, PFOMs, have been synthesized. Depending on the workup procedure used, two types of compounds were prepared. The first PFOM was a quasi Wells-Dawson type compound, [H2F6NaV(V)W17O56]8-, and the second a mixture of vanadium-substituted polyfluorooxometalates of the Keggin structure, XV(IV)W11F(n)O(40-n) (X = H2, V, W; n = 1-4). From the X-ray diffraction analysis, [H2F6NaV(V)W17O56]8- has an elliptic (egg) shape with a central sodium atom surrounded by six fluorine atoms in a trigonal prism coordination. One may differentiate between two types of addenda atoms to be found in belt and capped positions. According to 1H, 19F, and 51V NMR analysis, it is concluded that vanadium is isomorphically substituted in both the belt and capped position of [H2F6NaV(V)W17O56]8-. The mixture of vanadium-substituted PFOMs of the Keggin structure was shown, by HPLC and ESR, to contain at least two species of different charge and of a different vanadium environment. The [H2F6NaV(V)W17O56]8- PFOM was active for the catalytic aerobic oxidation of alkyl aromatic compounds in biphasic (water-catalyst and substrate) media. The reaction selectivity (autoxidation versus oxydehydrogenation) depended on the substrate and reaction conditions such as temperature and oxygen pressure. The selectivity to oxydehydrogenation was significantly higher compared to the prototypical cobalt acetate catalytic system.",
author = "Khenkin, {Alexander M.} and Ronny Neumann",
year = "2000",
month = "8",
day = "7",
doi = "10.1021/ic990606s",
language = "English",
volume = "39",
pages = "3455--3462",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "16",

}

TY - JOUR

T1 - Mixed-addenda vanadium-substituted polyfluorooxometalates

T2 - Synthesis, characterization, and catalytic aerobic oxidation

AU - Khenkin, Alexander M.

AU - Neumann, Ronny

PY - 2000/8/7

Y1 - 2000/8/7

N2 - For the first time, mixed-addenda vanadium-substituted polyfluorooxometalates, PFOMs, have been synthesized. Depending on the workup procedure used, two types of compounds were prepared. The first PFOM was a quasi Wells-Dawson type compound, [H2F6NaV(V)W17O56]8-, and the second a mixture of vanadium-substituted polyfluorooxometalates of the Keggin structure, XV(IV)W11F(n)O(40-n) (X = H2, V, W; n = 1-4). From the X-ray diffraction analysis, [H2F6NaV(V)W17O56]8- has an elliptic (egg) shape with a central sodium atom surrounded by six fluorine atoms in a trigonal prism coordination. One may differentiate between two types of addenda atoms to be found in belt and capped positions. According to 1H, 19F, and 51V NMR analysis, it is concluded that vanadium is isomorphically substituted in both the belt and capped position of [H2F6NaV(V)W17O56]8-. The mixture of vanadium-substituted PFOMs of the Keggin structure was shown, by HPLC and ESR, to contain at least two species of different charge and of a different vanadium environment. The [H2F6NaV(V)W17O56]8- PFOM was active for the catalytic aerobic oxidation of alkyl aromatic compounds in biphasic (water-catalyst and substrate) media. The reaction selectivity (autoxidation versus oxydehydrogenation) depended on the substrate and reaction conditions such as temperature and oxygen pressure. The selectivity to oxydehydrogenation was significantly higher compared to the prototypical cobalt acetate catalytic system.

AB - For the first time, mixed-addenda vanadium-substituted polyfluorooxometalates, PFOMs, have been synthesized. Depending on the workup procedure used, two types of compounds were prepared. The first PFOM was a quasi Wells-Dawson type compound, [H2F6NaV(V)W17O56]8-, and the second a mixture of vanadium-substituted polyfluorooxometalates of the Keggin structure, XV(IV)W11F(n)O(40-n) (X = H2, V, W; n = 1-4). From the X-ray diffraction analysis, [H2F6NaV(V)W17O56]8- has an elliptic (egg) shape with a central sodium atom surrounded by six fluorine atoms in a trigonal prism coordination. One may differentiate between two types of addenda atoms to be found in belt and capped positions. According to 1H, 19F, and 51V NMR analysis, it is concluded that vanadium is isomorphically substituted in both the belt and capped position of [H2F6NaV(V)W17O56]8-. The mixture of vanadium-substituted PFOMs of the Keggin structure was shown, by HPLC and ESR, to contain at least two species of different charge and of a different vanadium environment. The [H2F6NaV(V)W17O56]8- PFOM was active for the catalytic aerobic oxidation of alkyl aromatic compounds in biphasic (water-catalyst and substrate) media. The reaction selectivity (autoxidation versus oxydehydrogenation) depended on the substrate and reaction conditions such as temperature and oxygen pressure. The selectivity to oxydehydrogenation was significantly higher compared to the prototypical cobalt acetate catalytic system.

UR - http://www.scopus.com/inward/record.url?scp=0034617624&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034617624&partnerID=8YFLogxK

U2 - 10.1021/ic990606s

DO - 10.1021/ic990606s

M3 - Article

VL - 39

SP - 3455

EP - 3462

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 16

ER -