三价超铀元素镅冠醚包合物的合成与表征  

Synthesis and characterization of americium(Ⅲ)crown ether inclusion complexes

作　　者：李凯[1] 王俊人 代星 程丽葳 张海龙 林健 王亚星[1] 王殳凹 Kai Li;Junren Wang;Xing Dai;Liwei Cheng;Hailong Zhang;Jian Lin;Yaxing Wang;Shuao Wang(State Key Laboratory of Radiation Medicine and Protection,Soochow University,Suzhou 215123,China;School of Nuclear Science and Technology,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]苏州大学放射医学与辐射防护国家重点实验室,苏州215123 [2]西安交通大学核科学与技术学院,西安710049

出　　处：《科学通报》2024年第23期3404-3411,共8页Chinese Science Bulletin

基　　金：国家重点研发计划(2022YFE0105300);国家自然科学基金(22222606,21825601,22206143,U22B20139,U20B2019);江苏省自然科学基金(BK20211546)资助。

摘　　要：本文报道了95号元素镅(Am)的冠醚包合物[Am(NO_(3))_(2)(18-crown-6)]_(3)·[Am(NO_(3))_(6)](简写为Am-18C6)合成、单晶结构和固体紫外-可见-近红外光谱.X射线单晶衍射表明,Am-18C6晶体属于单斜晶系中的C2/m空间群,非对称单元由[Am(NO_(3))_(6)]^(3-)、[Am(NO_(3))_(2)(18C6)]^(+)和二重无序的[Am(NO_(3))_(2)(18C6)]^(+)孤立离子对组装而成.我们系统比较了Am-O键长与镧系同构晶体中Nd-O键长的差异,并将其与密度泛函理论(density function theory,DFT)计算的理论键长进行了对比.结果表明,Am^(3+)和Nd^(3+)的电子密度变化截然不同,Am^(3+)表现出明显地失去5f电子密度,这意味着Am^(3+)的5f电子在向着O–Am配位键中心延展和极化,而Nd^(3+)并未表现出此特性.本工作对加深三价超铀元素和大环配体之间主客体相互作用理解提供了帮助,为设计新型镧锕分离萃取剂提供了结构模型与理论基础.The coordination chemistry of americium holds significant importance in the fields of spent fuel reprocessing and nuclearwaste disposal. However, owing to its scarcity and inherent high radioactivity, only a limited number of radiochemicallaboratories worldwide possess the ability to handle americium, making the study of its coordination chemistryexceptionally challenging. Compared with research on uranium, neptunium, and plutonium, studies on the coordinationchemistry of americium are relatively scarce. The number of reported crystal structures for high-valent uranium reaches7000, while those for are 399 and 254, respectively. In contrast, there are only 113 entries for americium crystal structuresin the Cambridge Structural Database. This has resulted in limited knowledge about the chemistry of americium elements.Crown ethers are a class of macrocyclic ligands with adjustable cavity sizes, molecular architectures, and donor atoms thatexhibit selective complexation abilities for metal ions. Studies on solid-state chemistry involving crown ethers andtransuranic elements are limited;thus far, only a few complexes comprising transuranic elements and crown ethers havebeen synthesized and characterized. To the best of our knowledge, there have been limited thermodynamic studies onamericium and crown ether ligands, with no synthesis or structural determination of the americium crown ether complex.Herein, we report the synthesis, single-crystal structure, and solid-state ultraviolet–visible–near-infrared spectroscopyanalysis of the first americium crown ether inclusion complex, [Am(NO_(3))_(2)(18-crown-6)]_(3)·[Am(NO_(3))_(6)] (denoted as Am18C6).Single-crystal X-ray diffraction reveals that the Am-18C6 structure is isomorphic to the synthesized Nd-18C6, andboth structures crystallize in the monoclinic space group of C2/m, which is assembled by independent ionic pairs including[M(NO_(3))_(6)]^(3−) (M1), [M(NO_(3))_(2)(18C6)]^(+) (M2) and disordered [M(NO_(3))_(2)(18C6)]^(+) (M3). The analysis of the structures r

关 键 词：超铀元素 镅 配合物 密度泛函理论 

分 类 号：O641.4[理学—物理化学]