Aluminium anions with an unoccupied orbital are generally considered as highly difficult synthetic targets, as aluminium is the most electropositive element in the p block. Stabilizing effects from two nitrogen substituents and/or the coordination of a Lewis base were recently used to synthesize the first examples of anionic nucleophilic aluminium species. Here we show the synthesis and properties of a potassium salt of a non-stabilized dialkylaluminium anion that exhibits very strong basicity, which reflects the electropositive character of aluminium. An X-ray diffraction analysis revealed a monomeric structure and the shortest Al-K distance hitherto reported. The ultraviolet visible spectrum in combination with density functional theory calculations suggests an electronic structure characterized by a lone pair of electrons and an unoccupied p orbital on the aluminium centre. This species readily deprotonates benzene to form the corresponding (hydrido)(phenyl)aluminate. Reactions with other electrophiles corroborate the nucleophilicity of the aluminium centre.

中文翻译：

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具有强碱性和亲核性的烷基取代的铝阴离子。

具有空位轨道的铝阴离子通常被认为是非常困难的合成靶标，因为铝是p嵌段中最具正电性的元素。来自两个氮取代基的稳定作用和/或路易斯碱的配位作用最近被用于合成阴离子亲核铝物质的第一个实例。在这里，我们显示了非稳定的二烷基铝阴离子钾盐的合成和性能，该钾盐具有很强的碱性，反映了铝的正电特性。X射线衍射分析显示迄今报道的单体结构和最短的Al-K距离。紫外可见光谱与密度泛函理论计算相结合，提出了一种电子结构，其特征在于铝对中心具有一对孤电子和一个未占据的p轨道。这种物质很容易使苯去质子化，形成相应的（氢化）（苯基）铝酸盐。与其他亲电子试剂的反应证实了铝中心的亲核性。