34. Tetrabutylammonium Tetrachlorooxo‐Technetate(V)

Davison, Alan; Trop, Harvey S.; Depamphilis, B. V.; Jones, Alun G.; Thomas, Rudy; Jurisson, Silvia S.

doi:10.1002/9780470132524.ch34

Cited by 61 publications

(21 citation statements)

References 7 publications

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“…Solid ammonium pertechnetate (NH 4 TcO 4 ) was treated with H 2 O 2 to oxidize any reduced forms of 99 Tc . Standardization of prepared aqueous ammonium pertechnetate solutions was conducted according to established UV/Vis procedures , . The H 3 PW 12 O 40 (PW 12 ) and H 4 SiW 12 O 40 (SiW 12 ) Keggin anions were purchased from Sigma‐Aldrich and used without further purification.…”

Section: Methodsmentioning

confidence: 99%

Strategies for the Photoreduction of Tc‐99 Pertechnetate to Low‐Valent Tc by Keggin Polyoxometalates

et al. 2020

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Technetium‐99 (half‐life of 2.1 × 105 yrs, βmax = 0.29 MeV) is a hazardous radiological contaminant, which, in its predominant form of pertechnetate (TcO4–), is highly mobile in the environment. Most strategies for the removal of pertechnetate from the environment involve uptake and/or absorption of pertechnetate using resins, clays, cationic metal‐organic frameworks and even thorium borate ceramic like materials. Alternative approaches have involved the reduction and subsequent sequestration of lower valent technetium species using iron, sulfides, or iron sulfides. Our lab has explored this strategy using the lacunary alpha‐2 Wells–Dawson polyoxometalate (α2‐[P2W17O61]10–) to both reduce and sequester lower valent technetium, and we have reported on the ligand features that stabilize the reduced species. In this work we investigate the potential of “plenary” Keggin POMs (XW12O40n–) (X = P, Si, Al, n = 3, 4, 5, respectively) to both reduce TcO4– and stabilize the reduced Tc species. Specifically, we report on the mechanism by which the reduction of technetium occurs and find that PW12, SiW12, and AlW12 promote the reduction of TcO4– to lower valent states. X‐ray absorption spectroscopy was used to confirm a combination of TcIV {in the form of TcO2·2H2O and Tc2(µ‐O)24+} and TcV, which is subsequently complexed into a POM defect as a TcV=O species.

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Section: Methodsmentioning

confidence: 99%

Strategies for the Photoreduction of Tc‐99 Pertechnetate to Low‐Valent Tc by Keggin Polyoxometalates

et al. 2020

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“…The resulting colorless aqueous solution was standardized using a well‐established UV/Vis protocol. (TBA)TcOCl 4 and (TBA)TcNCl 4 were prepared from NH 4 TcO 4 according to established procedures …”

Section: Methodsmentioning

confidence: 99%

Synthesis and Characterization of Non‐Aqueous [Tc^XM‐PW₁₁O₃₉]ⁿ^– with M = O, N: Comparing Tc^V and Tc^VI in Metal Oxide Matrices

et al. 2019

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Technetium-99, a prevalent by-product of the nuclear fuel cycle, is a transition metal with 9 accessible oxidation states and a half-life of 2.1 × 10 5 years. 99 Tc VII has been found in the environment surrounding National Lab sites and fuel reprocessing centers, and its separation and long-term storage is complicated by its extensive redox chemistry. In our prior work we have reported the synthesis and reduction of Tc V O to Tc IV O in α 1 -and α 2 -Wells-Dawson P 2 W 17 O 61 10polyoxometalates and reported on the polyoxometalate features that promote reduc- [a]

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“…All syntheses were performed in a laboratory approved for low‐level use of radioactivity with appropriate radioactive material handling procedures. (NBu 4 )TcOCl 4 was prepared from NH 4 TcO 4 according to an established procedure 2. Ligands K 9 Li(α 1 ‐P 2 W 17 O 61 ) ( α 1 ) and K 10 (α 2 ‐P 2 W 17 O 61 ) ( α 2 ) were prepared as described in the literature 9.…”

Section: Methodsmentioning

confidence: 99%

“…One of the most useful synthetic starting materials is (NBu 4 )TcOCl 4 , which provides the Tc V O core in a variety of square pyramidal complexes 1. One key problem with (NBu 4 )TcOCl 4 is that it can disproportionate in water to form TcO 4 – and a variety of Tc IV species, especially TcO 2 · 2H 2 O 2. This is especially problematic in syntheses using ligands that have “hard” donor atoms, such as oxygen, where the stability with the “soft” Tc V =O 3+ core may be low.…”

Section: Introductionmentioning

confidence: 99%

Insights into Stabilization of the ⁹⁹Tc^VO Core for Synthesis of ⁹⁹Tc^VO Compounds

et al. 2014

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Synthesis of technetium-99 ( 99 Tc; t 1/2 : 2.1ϫ 10 5 years, β max : 253 keV) materials is of importance in studies of the nuclear fuel cycle where Tc is a major fission product (6 % thermal yield from 235 U and 239 Pu), in understanding radioactive tank waste composition, and in identifying 99m Tc compounds for nuclear medicine imaging. One of the most useful synthetic starting materials, (NBu 4 )TcOCl 4 , is susceptible to disproportionation in water to form TcO 4 and Tc IV species, especially TcO 2 ·2H 2 O. This unwanted reaction is especially problematic when working with ligands bearing "hard" donor atoms, such as oxygen, where the stability with the "soft" Tc V =O 3+ core may be low. Polyoxometalates (POMs) are such ligands. They possess defect sites with four hard oxygen atoms and show low (ca. 10 8 ) stability constants with transition metals. Tc complexes of POMs are molecular-level models for Tc metal oxide solid-state materials and can provide information [a]

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34. Tetrabutylammonium Tetrachlorooxo‐Technetate(V)

Cited by 61 publications

References 7 publications

Strategies for the Photoreduction of Tc‐99 Pertechnetate to Low‐Valent Tc by Keggin Polyoxometalates

Strategies for the Photoreduction of Tc‐99 Pertechnetate to Low‐Valent Tc by Keggin Polyoxometalates

Synthesis and Characterization of Non‐Aqueous [Tc^XM‐PW₁₁O₃₉]ⁿ^– with M = O, N: Comparing Tc^V and Tc^VI in Metal Oxide Matrices

Insights into Stabilization of the ⁹⁹Tc^VO Core for Synthesis of ⁹⁹Tc^VO Compounds

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34. Tetrabutylammonium Tetrachlorooxo‐Technetate(V)

Cited by 61 publications

References 7 publications

Strategies for the Photoreduction of Tc‐99 Pertechnetate to Low‐Valent Tc by Keggin Polyoxometalates

Strategies for the Photoreduction of Tc‐99 Pertechnetate to Low‐Valent Tc by Keggin Polyoxometalates

Synthesis and Characterization of Non‐Aqueous [TcXM‐PW11O39]n– with M = O, N: Comparing TcV and TcVI in Metal Oxide Matrices

Insights into Stabilization of the 99TcVO Core for Synthesis of 99TcVO Compounds

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Synthesis and Characterization of Non‐Aqueous [Tc^XM‐PW₁₁O₃₉]ⁿ^– with M = O, N: Comparing Tc^V and Tc^VI in Metal Oxide Matrices

Insights into Stabilization of the ⁹⁹Tc^VO Core for Synthesis of ⁹⁹Tc^VO Compounds