分级结晶法从镧系元素中高效分离高价锕系离子，这一成果由西安交通大学林健研究小组经过不懈努力而取得。相关论文于2025年2月28日发表于国际顶尖学术期刊《结构化学》杂志上。

在本研究中，课题组引入了3,6-二-2-吡啶-1,2,4,5-四嗪（L1），其吡啶-2-羧基（吡啶-2-羰基）-腙（L2）的水解产物，可以高选择性和高效率地在Ln（III）阳离子上分步结晶U（VI）离子。通过水解诱导的C-N键裂解，L2作为四齿配体，与两个UO₂²⁺离子以平面排列形成零维配位体[(UO₂)₂(μ₃-O)(L2)(CH₃COO)]·DMF (U-L2)，而镧系离子（Ln = La, Pr, Nd, Sm, Eu, Gd, Tb， Yb和Lu）由于无法实现类似的配位而留在溶液中。这种选择性结晶策略在U（VI）和Ln（III）之间产生了特殊的分离因子，U（VI）和Sm（III）之间的分离因子为756276，是迄今为止报道的最高分离因子。

此外，这种分级结晶分离过程可以在温和的环境条件下以高分离因子实现，从而开发出一种快速、安全、节能的高氧化态锕系元素与镧系元素的一次性分离策略。

据悉，锕系元素与镧系元素的分离是推进核废料管理和维持核能发展的关键，但由于这些f块元素的复杂化学行为，它仍然是一个艰巨的挑战。

附：英文原文

Title: Highly efficient separation of high-valent actinide ions from lanthanides via fractional crystallization

Author: anonymous

Issue&Volume: 2025-02-28

Abstract: Partitioning of actinides from lanthanides is pivotal for advancing nuclear waste management and sustaining nuclear energy development, yet it remains a formidable challenge due to the intricate chemical behavior of these f-block elements. In this study, we introduce 3,6-di-2-pyridyl-1,2,4,5-tetrazine (L1), whose hydrolysis product of pyridine-2-carbox-aldehyde (pyridine-2-carbonyl)-hydrazone (L2) can fractionally crystallize U(VI) ions over Ln(III) cations with high selectivity and efficiency. Through hydrolysis-induced C–N bond cleavage, L2 acts as a tetradentate ligand, coordinating with two UO₂²⁺ ions in a planar arrangement to form a zero-dimensional cluster, [(UO₂)₂(μ₃-O)(L2)(CH₃COO)]·DMF (U-L2), while lanthanide ions (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Yb, and Lu) remain in solution due to their inability to achieve similar coordination. This selective crystallization strategy yields exceptional separation factors between U(VI) and Ln(III), with a separation factor of 756276 between U(VI) and Sm(III), the highest reported to date. Furthermore, this fractional crystallization separation process can be achieved under mild ambient conditions with high separation factors, enabling the development of a rapid, safe, and energy-efficient strategy for once-through separation of high oxidation state actinides from lanthanides.

DOI: 10.1016/j.cjsc.2025.100562

Source: http://cjsc.ac.cn/cms/issues/772