Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QR, UK.
Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O. Box 35, Jyväskylä, FI-40014, Finland.
Chem Commun (Camb). 2020 Jan 18;56(6):944-947. doi: 10.1039/c9cc09018e. Epub 2019 Dec 19.
The 1 : 1 reactions of uranium(iv) tetrakis(borohydride) with the sodium and potassium salts of the cyclobutadienyl anion [C(SiMe)] (Cb'''') produce the half-sandwich complexes [Na(12-crown-4)][U(η-Cb'''')(BH)] and [U(η-Cb'''')(μ-BH){K(THF)}]. In the 1 : 2 reaction of U(BH) with NaCb'''', formation of [U(η-Cb'''')(η-CH(SiMe)-κ-(CHSiMe)(BH))] reveals that a Cb'''' ligand undergoes an intramolecular deprotonation, resulting in an allyl/tuck-in bonding mode. A computational study reveals that the uranium-Cb'''' bonding has an appreciable covalent component with contributions from the uranium 5f and 6d orbitals.
铀(iv)四(硼氢)与环丁二烯阴离子[C(SiMe)]（Cb'''）的钠盐和钾盐的 1:1 反应生成半夹心配合物[Na(12-冠-4)][U(η-Cb'''')(BH)]和[U(η-Cb'''')(μ-BH){K(THF)}]。在 U(BH)与 NaCb'''的 1:2 反应中，形成[U(η-Cb'''')(η-CH(SiMe)-κ-(CHSiMe)(BH))]表明 Cb''''配体经历了分子内去质子化，导致烯丙基/内插键合模式。计算研究表明，铀-Cb''''键具有可观的共价成分，来自铀的 5f 和 6d 轨道。
