A neutral cyclic aluminium (I) trimer.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41618085.
- Also identified by DOI 10.1038/s41467-026-68432-1 and PMC identifier 12913658.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
As part of the quest to develop metal-based redox chemistry beyond the d-block, low oxidation state aluminium complexes have gained wide recognition as discrete and versatile 2-electron reductants. Despite reports of monomeric, dimeric and tetrameric neutral structures, as well as a range of charged aluminyl compounds, neutral trimeric structures have remained notably absent. Furthermore, trimeric nuclearity has previously not been considered when investigating reaction mechanisms. Here, we report two neutral Al<sup>I</sup> trimers, cyclotrialumanes. The molecules are extensively characterised using both experimental and computational techniques, with the Al-Al bonds described as principally covalent in nature and the trimeric structure shown to be retained in solution. The cyclotrialumanes are highly reactive, activating a range of small molecules and unsaturated substrates (e.g. H<sub>2</sub>, alkyne, benzene). Most significantly, through a series of extraordinary reactions with ethylene, the cyclotrialumanes are shown to react directly as trimers, forming 5- and 7-membered Al-C ring systems.