Department of Chemistry & Biochemistry, University of California, Los Angeles, California 90095, USA.
Inorg Chem. 2012 Mar 5;51(5):2902-16. doi: 10.1021/ic202163m. Epub 2012 Feb 16.
Diuranium μ-η(6),η(6)-arene complexes supported by ketimide ligands were synthesized and characterized. Disodium or dipotassium salts of the formula M(2)(μ-η(6),η(6)-arene)U(NC(t)BuMes)(3) (M = Na or K, Mes = 2,4,6-C(6)H(2)Me(3)) and monopotassium salts of the formula K(μ-η(6),η(6)-arene)U(NC(t)BuMes)(3) (arene = naphthalene, biphenyl, trans-stilbene, or p-terphenyl) were both observed. Two different salts of the monoanionic, toluene-bridged complexes are also described. Density functional theory calculations have been employed to illuminate the electronic structure of the μ-η(6),η(6)-arene diuranium complexes and to facilitate the comparison with related transition-metal systems, in particular (μ-η(6),η(6)-C(6)H(6))VCp. It was found that the μ-η(6),η(6)-arene diuranium complexes were isolobal with (μ-η(6),η(6)-C(6)H(6))VCp and that the principal arene-binding interaction was a pair of δ bonds (total of 4e) involving both metals and the arene lowest unoccupied molecular orbital. Reactivity studies have been carried out with the mono- and dianionic μ-η(6),η(6)-arene diuranium complexes, revealing contrasting modes of redox chemistry as a function of the system's state of charge.
偕二氮戊环μ-η(6),η(6)-芳基配合物由酰亚胺配体支持合成并进行了表征。偕二氮戊环μ-η(6),η(6)-芳基二铀配合物的二钠盐或二钾盐的化学式为 M(2)(μ-η(6),η(6)-芳基)U(NC(t)BuMes)(3)（M = Na 或 K，Mes = 2,4,6-C(6)H(2)Me(3)）和单钾盐的化学式为 K(μ-η(6),η(6)-芳基)U(NC(t)BuMes)(3)（芳基=萘、联苯、反式二苯乙烯或对三联苯）都被观察到。还描述了两种不同的单阴离子、甲苯桥联配合物的盐。密度泛函理论计算被用来阐明μ-η(6),η(6)-芳基二铀配合物的电子结构，并有助于与相关的过渡金属体系进行比较，特别是(μ-η(6),η(6)-C(6)H(6))VCp。发现μ-η(6),η(6)-芳基二铀配合物与(μ-η(6),η(6)-C(6)H(6))VCp是等电子体，主要的芳基结合相互作用是一对δ键（总共 4e），涉及两个金属和芳基最低未占据分子轨道。对单阴离子和二阴离子μ-η(6),η(6)-芳基二铀配合物进行了反应性研究，揭示了氧化还原化学的对比模式，这是作为系统电荷状态的函数。
