Observation of a promethium complex in solution

• 成果类型: Article
• 署名作者: Driscoll, Darren M.; White, Frankie D.; Pramanik, Subhamay; Einkauf, Jeffrey D.; Ravel, Bruce; Bykov, Dmytro; Roy, Santanu; Mayes, Richard T.; Delmau, Laetitia H.; Cary, Samantha K.; Dyke, Thomas; Miller, April; Silveira, Matt; Vancleve, Shelley M.; Davern, Sandra M.; Jansone-Popova, Santa; Popovs, Ilja; Ivanov, Alexander S.
• 署名单位: United States Department of Energy (DOE); Oak Ridge National Laboratory; United States Department of Energy (DOE); Oak Ridge National Laboratory; National Institute of Standards & Technology (NIST) - USA; United States Department of Energy (DOE); Oak Ridge National Laboratory
• 刊物名称: Nature
• ISSN/ISSBN: 0028-6389
• DOI: 10.1038/s41586-024-07267-6
• 发表日期: 2024-05-23
• 关键词: initio molecular-dynamics; ab-initio; lanthanide contraction; lanthanoid(iii) ions; absorption; chemistry; SPECTRA; sphere; pseudopotentials; approximation

摘要

Lanthanide rare-earth metals are ubiquitous in modern technologies 1-5 , but we know little about chemistry of the 61st element, promethium (Pm) 6 , a lanthanide that is highly radioactive and inaccessible. Despite its importance 7,8 , Pm has been conspicuously absent from the experimental studies of lanthanides, impeding our full comprehension of the so-called lanthanide contraction phenomenon: a fundamental aspect of the periodic table that is quoted in general chemistry textbooks. Here we demonstrate a stable chelation of the 147Pm radionuclide (half-life of 2.62 years) in aqueous solution by the newly synthesized organic diglycolamide ligand. The resulting homoleptic PmIII complex is studied using synchrotron X-ray absorption spectroscopy and quantum chemical calculations to establish the coordination structure and a bond distance of promethium. These fundamental insights allow a complete structural investigation of a full set of isostructural lanthanide complexes, ultimately capturing the lanthanide contraction in solution solely on the basis of experimental observations. Our results show accelerated shortening of bonds at the beginning of the lanthanide series, which can be correlated to the separation trends shown by diglycolamides 9-11 . The characterization of the radioactive PmIII complex in an aqueous environment deepens our understanding of intra-lanthanide behaviour 12-15 and the chemistry and separation of the f-block elements 16 . Stable chelation of the 147Pm radionuclide in aqueous solution by the newly synthesized organic diglycolamide ligand is demonstrated and the resulting complex studied, showing accelerated shortening of bonds at the beginning of the lanthanide series.