Photoreduction of⁹⁹Tc Pertechnetate by Nanometer-Sized Metal Oxides: New Strategies for Formation and Sequestration of Low-Valent Technetium

Abstract

ABSTRACTproduct. The reduction and incorporation of TcO 4 -was accomplished in a "one pot" reaction using both sunlight and UV irradiation, and monitored as a function of time using multinuclear NMR and radio TLC. The process was further probed by the "step-wise" generation of reduced α 2 -P 2 W 17 O 61 12-through bulk electrolysis followed by the addition of TcO 4 -. serving as models for metal oxides, POMs may also provide a suitable platform to study the molecular level dynamics and mechanisms of the reduction and incorporation of Tc into a material.

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

“…This fundamental study, along with our previous reports using the α 2 ‐[P 2 W 17 O 61 ] 10– and Keggin ions for binding of Tc,, demonstrate that POMs have sites that can stabilize different Tc oxidation states and can be useful to understand the coordination chemistry of reduced Tc. Specifically, we demonstrated the different coordination geometries and sites provided by POMs dictate the Tc oxidation states (IV and V).…”

“…The ITLC data of PW 12 : Tc A and SiW 12 : Tc A, from year 1, taken immediately after the bulk electrolysis reaction, correlates with the XANES and EXAFS data described above and supports the formation of a Tc V =O PW 11 species and a Tc IV species for the SiW 12 complex. In our previous work, we observed that when the reduced Tc is associated with the POM, for example, when the Tc V is incorporated into a defect site, such as in the α 2 P 2 W 17 , the activity is observed at or near the origin with significant tailing . We have also observed that radiolanthanides incorporated into the defect of α 2 P 2 W 17 exhibit similar ITLC data, where activity remains at the origin .…”

“…A previous study by our lab identified a method wherein a single material, a polyoxometalate (POM), both reduces TcO 4 – and sequesters the reduced 99 Tc covalently into the POM . In that study, the lacunary alpha‐2 Wells–Dawson POM (α 2 ‐[P 2 W 17 O 61 ] 10– ) was photoactivated by light and reduced by a sacrificial electron donor (2‐propanol) to α 2 ‐[P 2 W 17 O 61 ] 12– .…”

Polioxometalatoak: Elhuyar anaien ametsak bizirik dirau!

“…Esaterako, hondakin erreaktiboen desaktibaziorako erreminta baliagarri bezala ikertu dira askotan, teknezio, uranio edo neptunio katioiei lotzeko duten afinitate handia aprobetxatuz [11]. Hondakin-uren tratamenduari dagokionez, hainbeste industriatan erabiltzen diren koloratzaile eta pestiziden oxidazio heterogeneo katalitikoan sarri hartzen dute parte, baina baita konposatu kutsagarrien analisian ere.…”

“…Ildo beretik jarraituz, kutsatzaileak desagerraraztea baino are garrantzitsuago da hauen erabilera ekiditea. Ildo honetan, kloroan oinarritutako konposatuen ordezko «berde» bezala aurkeztu da [AlVW 11 O 40 ] 6-POM anioia, papergintzan, zuritzearekin lotutako egurraren deslignifikazio prozesurako [13].…”