Combining Low-Valent AlI and SnII Metal Centers for Small Molecule Activation

Löwl T, Maurer J, Roig N, Mai J, Langer J, Alonso M, Harder S (2025)

Publication Type: Journal article

Publication year: 2025

Journal

DOI: 10.1002/ejic.202500050

Abstract

Reaction of the AlI complex (DIPPBDI-H)AlˉK+ with the SnII complex (DIPPBDI)SnCl gave (DIPPBDI-H)AlSn(DIPPBDI) (1); DIPPBDI = HC[C(Me)N(DIPP)]2, DIPP = 2,6-diisopropylphenyl, DIPPBDI-H = H2C=C(N-DIPP)-C(H)=C(Me)-N-DIPP. The crystal structure shows an asymmetric complex with a planar but strongly distorted trigonal coordination geometry at Al and trigonal pyramidal coordination at Sn. This geometry supports a donor-acceptor bonding model in which (DIPPBDI-H)Alˉ donates an sp2 electron pair in an empty p-orbital of (DIPPBDI)Sn+. Computational analysis supports polar covalent Al-Sn bonding which based on EDA-NOCV analysis is best described as the interaction of two neutral open shell AlII/SnI fragments: (DIPPBDI-H)Al● / (DIPPBDI)Sn●. Effective-Oxidation-State (EOS) analysis assigns the oxidation states AlI/SnII supporting the description of the bond as a (DIPPBDI-H)Alˉ → (DIPPBDI)Sn+ donor-acceptor interaction. However, the rather low reliability index of only 58.1% suggests that this description is not fully representative for the electronic situation. Reacting the electron rich, polarized Ald+-Sndˉ bond with alkynes gave cis-insertion, indicating a concerted reaction with a four-membered ring transition state. Reaction with CO2 selectively gave Al-O2C-Sn insertion, supporting the nucleophilic character of the electron rich Sn centre. The dianionic (DIPPBDI-H)2ˉ ligand is in these reactions not inert and reacts as C-centered nucleophile with alkyne or CO2 resulting in dianionic tridentate ligands.

Authors with CRIS profile

Involved external institutions

Vrije Universiteit Brussel (VUB) Belgium (BE)

How to cite

APA:

Löwl, T., Maurer, J., Roig, N., Mai, J., Langer, J., Alonso, M., & Harder, S. (2025). Combining Low-Valent AlI and SnII Metal Centers for Small Molecule Activation. European Journal of Inorganic Chemistry. https://doi.org/10.1002/ejic.202500050

MLA:

Löwl, Tristan, et al. "Combining Low-Valent AlI and SnII Metal Centers for Small Molecule Activation." European Journal of Inorganic Chemistry (2025).

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