德国慕尼黑工业大学Inoue, Shigeyoshi团队报道了具有硅铝和硅铝特性含有铝-硅芯的阴离子。相关研究成果于2023年7月3日发表于国际顶尖学术期刊《自然—化学》。

长期以来，与铝具有多个键的分子物种一直是具有挑战性的合成目标。尽管最近在该领域发现了具有里程碑意义的发现，但异二聚体Al–E多键（其中E是第14族元素）仍然很罕见，仅限于高度极化的π-相互作用（Al=E+Al–E–）。

该文中，研究人员报道了三种铝基硅烷化物阴离子的分离，其特征是由庞大的取代基稳定的Al–Si核和Si–Na相互作用。单晶X射线衍射研究、光谱分析和密度泛函理论计算表明，Al–Si相互作用具有部分双键性质。初步的反应性研究通过两种共振结构支持了对化合物的描述：一种共振结构显示出Al–Si核中钠配位硅中心的主要亲核特征，如对卤代硅烷亲电试剂的类硅烷化反应和苯基乙炔的CH插入所示。

此外，研究人员报道了一种具有螯合钠阳离子的铝基硅烷化物。[2.2.2]穴状配体对Si–Na键的裂解增加了Al–Si核的双键特性，从而产生具有高铝硅（–Al=Si）特性的阴离子。

附：英文原文

Title: Anions featuring an aluminium–silicon core with alumanyl silanide and aluminata-silene characteristics

Author: Ludwig, Moritz, Franz, Daniel, Espinosa Ferao, Arturo, Bolte, Michael, Hanusch, Franziska, Inoue, Shigeyoshi

Issue&Volume: 2023-07-03

Abstract: Molecular species containing multiple bonds to aluminium have long been challenging synthetic targets. Despite recent landmark discoveries in this area, heterodinuclear Al–E multiple bonds (where E is a group-14 element) have remained rare and limited to highly polarized π-interactions (Al=E+Al–E–). Here we report the isolation of three alumanyl silanide anions that feature an Al–Si core stabilized by bulky substituents and a Si–Na interaction. Single-crystal X-ray diffraction studies, spectroscopic analysis and density functional theory calculations show that the Al–Si interaction possesses partial double bond character. Preliminary reactivity studies support this description of the compounds through two resonance structures: one that displays a predominant nucleophilic character of the sodium-coordinated silicon centre in the Al–Si core, as shown by silanide-like reactivity towards halosilane electrophiles and the CH-insertion of phenylacetylene. Moreover, we report an alumanyl silanide with a sequestered sodium cation. Cleavage of the Si–Na bond by [2.2.2]cryptand increases the double bond character of the Al–Si core to produce an anion with high aluminata-silene (–Al=Si) character.

DOI: 10.1038/s41557-023-01265-3

Source: https://www.nature.com/articles/s41557-023-01265-3