Herle Dominic, Sommer Sara, Dankert Fabian
Institute of Chemistry, University of Kassel, Heinrich-Plett-Str. 40, Kassel 34132, Germany.
J Am Chem Soc. 2025 Sep 10;147(36):33315-33323. doi: 10.1021/jacs.5c12746. Epub 2025 Aug 25.
Low-valent cadmium compounds have remained largely unexplored as electron reservoirs, with no precedent for their use in reduction or bond activation chemistry. Here, we address this gap by integrating low-valent aluminum into the cadmium coordination sphere. Aluminylene insertion into Cd{N(TMS)} affords bi- and trimetallic cadmium aluminyls and , featuring covalent yet tunable Al-Cd bonding. While is irreversibly formed, exhibits dynamic reactivity, enabling reversible [AlCp*] transfer─a rare and previously undocumented feature in heterobimetallic aluminum chemistry. Acting as a thermodynamically stable yet chemically reactive surrogate for free Al(I), enables selective Al(I) shuttling to B, Cd, Zn, and Ag substrates (compounds , -). The cooperative Al-Cd framework in and further promotes bond activation of heterocumulenes such as carbodiimides and CO, with serving as a source of nucleophilic cadmium─an unprecedented reactivity mode for this element (compounds -). Detailed quantum chemical calculations elucidate the electronic structures of and as well as the mechanism for both Al(I) transfer and heterocumulene insertion. These findings establish a platform for bimetallic cooperativity in small-molecule activation and lay the groundwork for Al(I)-based multimetallic systems relevant to future catalysis and main group/transition-metal synergy.
低价镉化合物作为电子储存库在很大程度上尚未得到充分研究，在还原或键活化化学中的应用也没有先例。在这里，我们通过将低价铝整合到镉的配位球中来填补这一空白。亚铝烯插入Cd{N(TMS)}中可得到双金属和三金属镉铝化物 和 ，其具有共价但可调节的Al-Cd键。虽然 是不可逆形成的，但 表现出动态反应性，能够实现可逆的[AlCp*]转移——这是异双金属铝化学中一种罕见且以前未被记录的特征。作为游离Al(I)的热力学稳定但化学反应性的替代物， 能够使Al(I)选择性地穿梭到B、Cd、Zn和Ag底物上（化合物 、 -）。 和 中的协同Al-Cd框架进一步促进了异累积物如碳二亚胺和CO的键活化， 作为亲核镉的来源——这是该元素前所未有的反应模式（化合物 -）。详细的量子化学计算阐明了 和 的电子结构以及Al(I)转移和异累积物插入的机制。这些发现为小分子活化中的双金属协同作用建立了一个平台，并为与未来催化及主族/过渡金属协同作用相关的基于Al(I)的多金属体系奠定了基础。
