Pyrch Mikaela M, Williams James M, Forbes Tori Z
Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
Chem Commun (Camb). 2019 Aug 14;55(63):9319-9322. doi: 10.1039/c9cc04393d. Epub 2019 Jul 17.
Crown-ether molecules are used in radiochemical separations due to their high selectivity for a range of metal cations. Previous investigations regarding the interactions of 18-crown-6 (18C6) with Np suggested the formation of a Np(v) inclusion complex, but also reported rapid reduction of Np(vi) to Np(v) in the presence of the ether molecule. Herein, we investigate the impact of crown ether functionalization by exploring the Np(v) and Np(vi) dicyclohexano-18-crown-6 (DCH-18C6) systems. Two [X(DCH-18C6)][Np(vi)OCl] compounds (X = K (1) and Na (2)) were crystallized and characterized by single crystal X-ray diffraction and Raman spectroscopy. Additional studies of Np(vi), Np(v), and Np(v)/Np(vi) in solution indicated redox stability in the presence of functionalized crowns and preferential crystallization of Np(vi) DCH-18C6 solids. These results indicate that functionalization of the crown can lead to higher resistance to radiolysis and increased stability of the Np(vi) oxidation state in solution.
冠醚分子因其对一系列金属阳离子具有高选择性而被用于放射化学分离。先前关于18-冠-6（18C6）与Np相互作用的研究表明形成了Np（v）包合物，但也报道了在醚分子存在下Np（vi）迅速还原为Np（v）。在此，我们通过探索Np（v）和Np（vi）二环己基-18-冠-6（DCH-18C6）体系来研究冠醚官能化的影响。两种[X（DCH-18C6）][Np（vi）OCl]化合物（X = K（1）和Na（2））通过单晶X射线衍射和拉曼光谱进行了结晶和表征。对溶液中的Np（vi）、Np（v）和Np（v）/Np（vi）的进一步研究表明，在官能化冠醚存在下具有氧化还原稳定性，并且Np（vi）DCH-18C6固体优先结晶。这些结果表明，冠醚的官能化可以导致更高的抗辐射分解能力，并提高溶液中Np（vi）氧化态的稳定性。
