Volume 64, Issue 24 e202505940
Research Article

Crystalline Silagermenides as Powerful Synthons: Unraveling π-Bonding and Lone Pair Effects in the Multiple Bonds of Heavier Main Group Analogs of the Vinyl Anion

Xue-Yi He

Xue-Yi He

Department of Chemistry and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen, 518055 China

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Qiuming Liang

Qiuming Liang

Department of Chemistry and Dongguan Key Laboratory for Data Science and Intelligent Medicine, Great Bay University, Dongguan, 523000 China

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Yanbo Mei

Corresponding Author

Yanbo Mei

Department of Chemistry and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen, 518055 China

Department of Chemistry and Dongguan Key Laboratory for Data Science and Intelligent Medicine, Great Bay University, Dongguan, 523000 China

E-mail: [email protected]; [email protected]

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Liu Leo Liu

Corresponding Author

Liu Leo Liu

Department of Chemistry and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen, 518055 China

E-mail: [email protected]; [email protected]

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First published: 07 April 2025

Graphical Abstract

Acyclic silagermenides are synthesized through a straightforward desilylation process. Their electronic properties are explored using DFT calculations, revealing a high-lying and polarized Si─Ge π bond. Reactions with electrophiles lead to nucleophilic substitution at the Si atom, giving germylene intermediates, which then undergo further transformation into unique main group compounds and unprecedented metal complexes.

Abstract

Compared to common vinyl anions, their heavier heteronuclear analog, silagermenides [R2Si═GeR]ˉ, remain exceedingly rare. Herein, we present a systematic investigation of silagermenides, synthesized via a straightforward desilylation route. We delve into the bonding characteristics, revealing a weak, polarized Si─Ge π bond with a significant nonbonded lone pair character at the β-Si position. This β-Si exhibits predominantly nucleophilic behavior, while the α-Ge position demonstrates subtly electrophilic tendencies, despite the presence of a vinylic, formally anionic Ge atom. This leads to the formation of silagermenide complexes in an unprecedented η2 coordination mode, as well as various silagermenes and germylenes with unconventional substituents. We also document the facile cleavage of the ambiphilic Si═Ge double bond, resulting in the transfer of a formal doubly reduced silylene and a formal germyliumylidene. Our findings expand the understanding of heavier main group analogs of the vinyl anion, with important implications for their synthesis and reactivity.

Conflict of Interests

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available in the Supporting Information of this article.

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