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Abstract Careful analysis of the crystals formed in the reduction of AriPr8AlI2(AriPr8=C6H‐2,6‐(C6H2‐2,4,6‐iPr3)2‐3,5‐iPr2) with sodium on sodium chloride showed them to contain the long sought‐after dialuminene AriPr8AlAlAriPr8(1) that forms alongside the previously characterized alanediyl :AlAriPr8. The single crystal X‐ray structure of1revealed a nearly planar,trans‐bent C(ipso)AlAlC(ipso) core with an Al−Al distance of 2.648(2) Å. The molecular and electronic structure of1are consistent with an Al−Al double dative interaction augmented with diradical character and stabilized by dispersion interactions. Density functional theory calculations showed that the reactivity of :AlAriPr8with dihydrogen involves1, not :AlAriPr8, as the reactive species. In contrast, the reaction of :AlAriPr8with ethylene gave two products, the 1,4‐dialuminacyclohexane AriPr8Al(C2H4)2AlAriPr8(2) and the aluminacyclopentane AriPr8Al(C4H8) (3), that can both form from the aluminacyclopropane intermediate AriPr8Al(C2H4). Although the [2+2+2] cycloaddition of1with two equivalents of ethylene was also calculated to be exergonic, it is likely to be kinetically blocked by the numerous isopropyl substituents surrounding the Al−Al bond. Attempts to fine‐tune the steric bulk of the terphenyl ligand to allow stronger Al−Al bonding were unsuccessful, leading to the isolation of the sodium salt of a cyclotrialuminene, Na2[AlAriPr6]3(4), instead of AriPr6AlAlAriPr6.
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This content will become publicly available on April 29, 2027
Unexpected dispersion-stabilized tris(terphenylthiolate) complexes, Ln(SAr iPr6 ) 3 , arising from two-electron reduction by Ln(SAr iPr6 ) 2 [Ar iPr6 = C 6 H 3 -2,6-(C 6 H 2 -2,6,4- i Pr 3 ) 2 ]
Attractive London dispersion effects were found to be responsible forca.half of the dissociation energy of the thiolate ligands in the first examples of M(EAriPr6)3complexes of any metal with any donor [AriPr6= C6H3-2,6-(C6H2-2,4,6-iPr3)2].
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- Award ID(s):
- 2503294
- PAR ID:
- 10693456
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Chemical Science
- Volume:
- 17
- Issue:
- 16
- ISSN:
- 2041-6520
- Page Range / eLocation ID:
- 8160 to 8167
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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