美国劳伦斯利弗莫尔国家实验室Deblonde, Gauthier J.-P.团队，报道了多金属氧酸盐作为配体在微克尺度上合成、分离和表征稀有同位素化合物。相关研究成果发表在2022年9月1日出版的《自然—化学》。

放射性化合物的合成和研究都受到其毒性、成本和同位素稀缺性的固有限制。使用小型无机或有机络合物的传统方法每次尝试通常需要毫克样品，对于某些同位素，这相当于世界年供应量。

该文中，研究人员证明了多金属氧酸盐（POMs）由于其高分子量和可控的溶解度特性，能够从微克数量方便地形成、结晶、处理和详细表征金属-配体复合物。制备了三种curium–POM复合物，每次合成的稀有同位素²⁴⁸Cm³⁺仅使用1–10μg，并通过单晶X射线衍射进行了表征，显示了八配位的Cm³⁺中心。此外，对几种f-嵌段元素-POM络合物（包括²⁴³Am³⁺和²⁴⁸Cm³⁺）的分光光度、荧光、NMR和拉曼分析表明，它们的溶液与固态化学以及锕系元素与镧系元素的行为之间存在着不明显的差异。

该POM驱动的策略代表了分离更稀有复合物的可行途径，特别是与锕或跨钙元素的复合物。

附：英文原文

Title: Polyoxometalates as ligands to synthesize, isolate and characterize compounds of rare isotopes on the microgram scale

Author: Colliard, Ian, Lee, Jonathan R. I., Colla, Christopher A., Mason, Harris E., Sawvel, April M., Zavarin, Mavrik, Nyman, May, Deblonde, Gauthier J.-P.

Issue&Volume: 2022-09-01

Abstract: The synthesis and study of radioactive compounds are both inherently limited by their toxicity, cost and isotope scarcity. Traditional methods using small inorganic or organic complexes typically require milligrams of sample—per attempt—which for some isotopes is equivalent to the world’s annual supply. Here we demonstrate that polyoxometalates (POMs) enable the facile formation, crystallization, handling and detailed characterization of metal–ligand complexes from microgram quantities owing to their high molecular weight and controllable solubility properties. Three curium–POM complexes were prepared, using just 1–10μg per synthesis of the rare isotope 248Cm3+, and characterized by single-crystal X-ray diffraction, showing an eight-coordinated Cm3+ centre. Moreover, spectrophotometric, fluorescence, NMR and Raman analyses of several f-block element–POM complexes, including 243Am3+ and 248Cm3+, showed otherwise unnoticeable differences between their solution versus solid-state chemistry, and actinide versus lanthanide behaviour. This POM-driven strategy represents a viable path to isolate even rarer complexes, notably with actinium or transcalifornium elements.

DOI: 10.1038/s41557-022-01018-8

Source: https://www.nature.com/articles/s41557-022-01018-8