A Discrete Trialane with a Near-Linear Al3 Axis

The
presence of inherent electronic unsaturation in aluminum predominantly
results in the formation of aluminum clusters, with very few examples
of compounds containing discrete chains of aluminum atoms in existence.
In this work, we present the successful synthesis and structural authentication
of a highly unusual trialane species with a near-linear chain of three
Al atoms, alongside a carbene-stabilized aluminyl anion ([LAlR2]−), an alternative product produced by
varying the reaction conditions. Quantum-chemical calculations have
been applied to elucidate the electronic structure and bonding of
these novel compounds. Additionally, we successfully trapped a reaction
intermediate using an alkyne, suggesting the intermediacy of a base-stabilized
monomeric alumylene (LRAl:), which is also investigated through computational
methods.

铝元素固有的电子不饱和性主要导致铝簇的形成，而含有离散铝原子链的化合物实例极为罕见。在本研究中，我们成功合成了结构认证的一种非常罕见的试烷类物质，其具有近乎线性的三铝原子链，并伴随着一个由亚甲基负离子稳定（[LAlR2]−）的铝基阴离子，这是通过改变反应条件产生的另一种产物。我们应用量子化学计算来阐明这些新型化合物的电子结构和键合性质。此外，我们使用炔烃成功捕获了一个反应中间体，这表明存在一个由碱稳定的单聚铝乙烯中间体（LRAl:），这一中间体亦通过计算方法进行了研究。