5 research outputs found
Hydrogen-Bond-Assisted Epoxidation of Homoallylic and Allylic Alcohols with Hydrogen Peroxide Catalyzed by Selenium-Containing Dinuclear Peroxotungstate.
No full textﾎｼ-ﾎｷ1:ﾎｷ1-Peroxo-Bridged Dinuclear Peroxotungstate Catalytically Active for Epoxidation of Olefins.
No full textEpoxidation of Alkenes with Hydrogen Peroxide Catalyzed by Selenium-Containing Dinuclear Peroxotungstate and Kinetic, Spectroscopic, and Theoretical Investigation of the Mechanism.
No full textReversible Deprotonation and Protonation Behaviors of a Tetra-Protonated γ-Keggin Silicodecatungstate
No full textThe potentiometric titration of a γ-Keggin tetra-protonated
silicodecatungstate, [γ-SiW<sub>10</sub>O<sub>34</sub>(H<sub>2</sub>O)<sub>2</sub>]<sup>4–</sup> (H<sub>4</sub>·<b>I</b>), with TBAOH (TBA = [(<i>n</i>-C<sub>4</sub>H<sub>9</sub>)<sub>4</sub>N]<sup>+</sup>) showed inflection points at 2
and 3 equiv of TBAOH. The <sup>1</sup>H, <sup>29</sup>Si, and <sup>183</sup>W NMR data suggested that the in situ formation of tri-,
doubly-, and monoprotonated silicodecatungstates, [γ-SiW<sub>10</sub>O<sub>34</sub>(OH)(OH<sub>2</sub>)]<sup>5–</sup> (H<sub>3</sub>·<b>I</b>), [γ-SiW<sub>10</sub>O<sub>34</sub>(OH)<sub>2</sub>]<sup>6–</sup> (H<sub>2</sub>·<b>I</b>), and [γ-SiW<sub>10</sub>O<sub>35</sub>(OH)]<sup>7–</sup> (H·<b>I</b>), with <i>C</i><sub>1</sub>, <i>C</i><sub>2<i>v</i></sub>, and <i>C</i><sub>2</sub> symmetries, respectively. Single crystals of TBA<sub>6</sub>·H<sub>2</sub>·<b>I</b> suitable for the X-ray structure
analysis were successfully obtained and the anion part was a monomeric
γ-Keggin divacant silicodecatungstate with two protonated bridging
oxygen atoms. Compounds H<sub>3</sub>·<b>I</b>, H<sub>2</sub>·<b>I</b>, and H·<b>I</b> were reversibly monoprotonated
to form H<sub>4</sub>·<b>I</b>, H<sub>3</sub>·<b>I</b>, and H<sub>2</sub>·<b>I</b>, respectively
Reversible Deprotonation and Protonation Behaviors of a Tetra-Protonated γ-Keggin Silicodecatungstate
No full textThe potentiometric titration of a γ-Keggin tetra-protonated
silicodecatungstate, [γ-SiW<sub>10</sub>O<sub>34</sub>(H<sub>2</sub>O)<sub>2</sub>]<sup>4–</sup> (H<sub>4</sub>·<b>I</b>), with TBAOH (TBA = [(<i>n</i>-C<sub>4</sub>H<sub>9</sub>)<sub>4</sub>N]<sup>+</sup>) showed inflection points at 2
and 3 equiv of TBAOH. The <sup>1</sup>H, <sup>29</sup>Si, and <sup>183</sup>W NMR data suggested that the in situ formation of tri-,
doubly-, and monoprotonated silicodecatungstates, [γ-SiW<sub>10</sub>O<sub>34</sub>(OH)(OH<sub>2</sub>)]<sup>5–</sup> (H<sub>3</sub>·<b>I</b>), [γ-SiW<sub>10</sub>O<sub>34</sub>(OH)<sub>2</sub>]<sup>6–</sup> (H<sub>2</sub>·<b>I</b>), and [γ-SiW<sub>10</sub>O<sub>35</sub>(OH)]<sup>7–</sup> (H·<b>I</b>), with <i>C</i><sub>1</sub>, <i>C</i><sub>2<i>v</i></sub>, and <i>C</i><sub>2</sub> symmetries, respectively. Single crystals of TBA<sub>6</sub>·H<sub>2</sub>·<b>I</b> suitable for the X-ray structure
analysis were successfully obtained and the anion part was a monomeric
γ-Keggin divacant silicodecatungstate with two protonated bridging
oxygen atoms. Compounds H<sub>3</sub>·<b>I</b>, H<sub>2</sub>·<b>I</b>, and H·<b>I</b> were reversibly monoprotonated
to form H<sub>4</sub>·<b>I</b>, H<sub>3</sub>·<b>I</b>, and H<sub>2</sub>·<b>I</b>, respectively
