We report the preparation of a range of alkali metal uranyl(VI) tri-bis(silyl)amide complexes [{M(THF)_x}{(μ-O)U(O)(N″)₃}] (1M) (N″ = {N(SiMe₃)₂}⁻, 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)₂(N″)₃][M(2,2,2-cryptand)] (3M, M = Li–Cs) and [U(O)₂(N″)₃][M(crown)₂] (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)₂(N″)₃][M(THF)_n] (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.

中文翻译：

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铀酰三双（甲硅烷基）酰胺碱金属接触和分离的离子对配合物

我们报道了一系列碱金属铀酰（VI）三双（甲硅烷基）酰胺配合物的制备[{M（THF）_x } {（μ-O）U（O）（N''）₃ }]（1M） （N″ ＝ {N（SiMe ₃）₂ } ^-，M ＝ Li，Na，x＝ 2； M ＝ K，x＝ 3； M ＝ K，Rb，Cs，x＝ 0），其包含静电碱金属铀酰-氧代相互作用。的反应1M与2,2,2-穴状配体或2当量的合适的冠醚导致分离的离子对物种的分离[U（O）₂（N“）₃ ] [M（2,2,2- cryptand）]（3M，M = Li–Cs）和[U（O）₂（N″）₃ ] [M（冠）₂ ]（4M，M = Li，冠= 12冠-4醚； M = Na–Cs，冠= 15冠-5醚）。晶体学研究与IR，拉曼光谱和UV-可见光谱的结合表明，1M系列采用固态的接触离子对基序，其中碱金属封盖了一个铀酰-氧代基团。在溶解于THF溶液后，失去了这种接触，而是观察到了分离的离子对基序，这可以通过分离[U（O）₂（N''）₃ ] [M（THF）_n ]（2M）来确认。 （M = Li，n = 4； M = Na，K，n= 6）。通过单晶X射线衍射，多核NMR光谱，IR，拉曼光谱和UV-vis光谱学以及元素分析对化合物进行了表征。