Probing the Extremes of Covalency in M−Al bonds: Lithium and Zinc Aluminyl Compounds. (31st August 2021)

• Record Type: Journal Article
• Authors: Roy, Matthew M. D.; Hicks, Jamie; Vasko, Petra; Heilmann, Andreas; Baston, Anne‐Marie; Goicoechea, Jose M.; Aldridge, Simon
• Is Part Of: Angewandte Chemie. Volume 133:Number 41(2021)
• Page Start: 22475
• Page End: 22480
• Publication Date: 2021-08-31
• Subjects: aluminium -- aluminyl -- lithium -- low-valent compounds -- zinc; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202109416
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Synthetic routes to lithium, magnesium, and zinc aluminyl complexes are reported, allowing for the first structural characterization of an unsupported lithium–aluminium bond. Crystallographic and quantum‐chemical studies are consistent with the presence of a highly polar Li−Al interaction, characterized by a low bond order and relatively little charge transfer from Al to Li. Comparison with magnesium and zinc aluminyl systems reveals changes to both the M−Al bond and the (NON)Al fragment (where NON=4, 5‐bis(2, 6‐diisopropylanilido)‐2, 7‐di‐tert‐butyl‐9, 9‐dimethylxanthene), consistent with a more covalent character, with the latter complex being shown to react with CO2 via a pathway that implies that the zinc centre acts as the nucleophilic partner. Abstract : We report the synthesis of the first example of a molecular compound featuring a Li−Al bond and a systematic analysis of the bonding in this and related Mg and Zn systems through structural, quantum‐chemical, and reactivity probes.