Completing the Heterocubane Family [Cp*AlE]4 (E = O, S, Se, and Te) by Selective Oxygenation and Sulfuration of [Cp*Al]4: Density Functional Theory Calculations of [Cp*AlE]4 and Reactivity of [Cp*AlO]4 toward Hydrolysis

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• 作者：Adrian C. Stelzer ; Peter Hrobárik ; Thomas Braun ; Martin Kaupp ; Beatrice Braun-Cula
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：May 16, 2016
• 年：2016
• 卷：55
• 期：10
• 页码：4915-4923
• 全文大小：489K
• 年卷期：0
• ISSN：1520-510X

文摘

The subvalent aluminum compound [Cp*Al]₄ (1) reacts with dioxygen, N₂O, or sulfur to yield the heterocubane complexes [Cp*AlX]₄ [X = O (2) and S (3)]. Treatment of [Cp*AlO]₄ (2) with (tBuO)₃SiOH gave [(tBuO)₃SiOAlO]₄ (6) and Cp*H. The structures and spectroscopic data of the Al clusters are supported by density functional theory (DFT) calculations, which also demonstrate the importance of noncovalent interactions (NCI) in oligomeric Al(I) complexes as well as in [Cp*AlS]₄ and the heavier homologues of Se and Te. The computed p>27p>Al NMR shifts indicate a deshielding at the Al centers with increasing electronegativity of the chalcogen atom as well as significant spin–orbit shielding effects within the heavier heterocubane [Al₄E₄] cores. Further hydrolysis of 6 with an additional amount of silanol in the presence of water resulted in the formation of [Al₄(OH)₆(OH₂)₂(OSiOtBu₃)₆] (7), which shows a structural motif found in boehmite and diaspore.