Closing Uranyl Polyoxometalate Capsules with Bismuth and Lead Polyoxocations

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• 作者：Olivier Renier ; Dr. Clé ; ment Falaise ; Harrison Neal ; Karoly Kozma and Prof. Dr. May Nyman
• 刊名：Angewandte Chemie
• 出版年：2016
• 出版时间：October 17, 2016
• 年：2016
• 卷：128
• 期：43
• 页码：13678-13682
• 全文大小：1792K
• ISSN：1521-3757

文摘

Uranyl polyoxometalate clusters are both fundamentally fascinating and potentially relevant to nuclear energy applications. With only ten years of development, there is still much to be discovered about heterometal derivatives and aqueous speciation and behavior. Herein, we show that it is possible to encapsulate the polyoxocations [Bi₆O₈]²⁺ and [Pb₈O₆]⁴⁺ in [(UO₂)(O₂)(OH)]₂₄²⁴⁻ (denoted Bi@U₂₄ and Pb@U₂₄) in pure form and high yields despite the fact that under aqueous conditions, these compounds are stable on opposite ends of the pH scale. Moreover, [Pb₈O₆]⁴⁺ is a formerly unknown Pb^II polynuclear species, both in solution and in the solid state. Raman spectroscopic and mass spectrometric analysis of the reaction solutions revealed the very rapid assembly of the nested clusters, driven by bismuth- or lead-promoted decomposition of excess peroxide, which inhibits U₂₄ formation. Experimental and simulated small-angle X-ray scattering data of Bi@U₂₄ and Pb@U₂₄ solutions revealed that this technique is very sensitive not only to the size and shape of the clusters, but also to the encapsulated species.