2022-09-01 アメリカ・ローレンスリバモア国立研究所(LLNL)
研究チームは、分子量や溶解度などの基本的な化学特性を利用することで、希少元素、毒性元素、放射性元素、希少元素の配位化合物を合成し、その特性をマイクログラムスケールの極微量で詳細に評価できることを実証した。この方法は、従来の方法よりも1000倍以上少ない材料で、地球上で最も研究が困難な元素の知識を深めるための画期的なツールとなる。
この方法は、アクチノイドや放射性ランタノイドのような希少同位体を含む多くの新しい化合物を発見し、研究するために使用される可能性がある。
＜関連情報＞
- https://www.llnl.gov/news/going-big-unlocking-study-some-rarest-most-toxic-elements-earth
- https://www.nature.com/articles/s41557-022-01018-8
ポリオキソメタレートを配位子としたマイクログラムスケールの希少同位体化合物の合成、単離および特性評価 Polyoxometalates as ligands to synthesize, isolate and characterize compounds of rare isotopes on the microgram scale
Ian Colliard,Jonathan R. I. Lee,Christopher A. Colla,Harris E. Mason,April M. Sawvel,Mavrik Zavarin,May Nyman & Gauthier J.-P. Deblonde
Nature Chemistry Published:01 September 2022
DOI:https://doi.org/10.1038/s41557-022-01018-8
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 1–10 μg 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.
