Influence of the 5f Orbitals on the Bonding and Reactivity in Organoactinides: Experimental and Computational Studies on a Uranium Metallacyclopropene

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• 作者：Lei Zhang ; Guohua Hou ; Guofu Zi ; Wanjian Ding ; Marc D. Walter
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：April 20, 2016
• 年：2016
• 卷：138
• 期：15
• 页码：5130-5142
• 全文大小：897K
• 年卷期：0
• ISSN：1520-5126

文摘

The synthesis, structure, and reactivity of a uranium metallacyclopropene were comprehensively studied. Reduction of (η⁵-C₅Me₅)₂UCl₂ (1) with potassium graphite (KC₈) in the presence of bis(trimethylsilyl)acetylene (Me₃SiC≡CSiMe₃) allows the first stable uranium metallacyclopropene (η⁵-C₅Me₅)₂U[η²-C₂(SiMe₃)₂] (2) to be isolated. Magnetic susceptibility data confirm that 2 is a U(IV) complex, and density functional theory (DFT) studies indicate substantial 5f orbital contributions to the bonding of the metallacyclopropene U-(η²-C═C) moiety, leading to more covalent bonds between the (η⁵-C₅Me₅)₂U²⁺ and [η²-C₂(SiMe₃)₂]^2– fragments than those in the related Th(IV) compound. Consequently, very different reactivity patterns emerge, e.g., 2 can act as a source for the (η⁵-C₅Me₅)₂U(II) fragment when reacted with alkynes and a variety of heterounsaturated molecules such as imines, bipy, carbodiimide, organic azides, hydrazine, and azo derivatives.