Centre for Radiochemistry Research, School of Chemistry , The University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom.
Inorg Chem. 2018 Jun 4;57(11):6571-6583. doi: 10.1021/acs.inorgchem.8b00715. Epub 2018 May 18.
We report the preparation of a range of alkali metal uranyl(VI) tri- bis(silyl)amide complexes [{M(THF) }{(μ-O)U(O)(N″)}] (1M) (N″ = {N(SiMe)}, M = Li, Na, x = 2; M = K, x = 3; M = K, Rb, Cs, x = 0) containing electrostatic alkali metal uranyl-oxo interactions. Reaction of 1M with 2,2,2-cryptand or 2 equiv of the appropriate crown ether resulted in the isolation of the separated ion pair species [U(O)(N″)][M(2,2,2-cryptand)] (3M, M = Li-Cs) and [U(O)(N″)][M(crown)] (4M, M = Li, crown = 12-crown-4 ether; M = Na-Cs, crown = 15-crown-5 ether). A combination of crystallographic studies and IR, Raman and UV-vis spectroscopies has revealed that the 1M series adopts contact ion pair motifs in the solid state where the alkali metal caps one of the uranyl-oxo groups. Upon dissolution in THF solution, this contact is lost, and instead, separated ion pair motifs are observed, which is confirmed by the isolation of [U(O)(N″)][M(THF) ] (2M) (M = Li, n = 4; M = Na, K, n = 6). The compounds have been characterized by single crystal X-ray diffraction, multinuclear NMR spectroscopy, IR, Raman, and UV-vis spectroscopies, and elemental analyses.
我们报告了一系列碱金属铀酰(VI)三双(硅基)酰胺配合物[{M(THF) }{(μ-O)U(O)(N″)}] (1M) (N″ = {N(SiMe)}，M = Li, Na, x = 2; M = K, x = 3; M = K, Rb, Cs, x = 0)的制备，其中包含静电碱金属铀酰-氧相互作用。1M 与 2,2,2-穴醚或 2 当量的合适冠醚反应，得到分离的离子对物种[U(O)(N″)][M(2,2,2-穴醚)] (3M, M = Li-Cs)和[U(O)(N″)][M(冠醚)] (4M, M = Li, 冠醚 = 12-冠-4 醚；M = Na-Cs, 冠醚 = 15-冠-5 醚)。晶体学研究、红外、拉曼和紫外可见光谱的结合表明，1M 系列在固态中采用接触离子对模式，其中碱金属覆盖铀酰-氧基团之一。在 THF 溶液中溶解时，这种接触会丢失，取而代之的是观察到分离的离子对模式，这通过分离[U(O)(N″)][M(THF) ] (2M) (M = Li, n = 4; M = Na, K, n = 6)得到证实。这些化合物通过单晶 X 射线衍射、多核 NMR 光谱、红外、拉曼和紫外可见光谱以及元素分析进行了表征。
