Formation, Structure and Reactivity of a Beryllium(0) Complex with Mgδ+−Beδ− Bond Polarization

Berthold C, Maurer J, Klerner L, Harder S, Buchner MR (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Angewandte Chemie International Edition Wiley

DOI: 10.1002/anie.202408422

Abstract

Attempts to create a novel Mg−Be bond by reaction of [(DIPePBDI*)MgNa]2 with Be[N(SiMe3)2]2 failed; DIPePBDI*=HC[(tBu)C=N(DIPeP)]2, DIPeP=2,6-Et2C-phenyl. Even at elevated temperatures, no conversion was observed. This is likely caused by strong steric shielding of the Be center. A similar reaction with the more open Cp*BeCl gave in quantitative yield (DIPePBDI*)MgBeCp* (1). The crystal structure shows a Mg−Be bond of 2.469(4) Å. Homolytic cleavage of the Mg−Be bond requires ΔH=69.6 kcal mol−1 (cf. CpBe−BeCp 69.0 kcal mol−1 and (DIPPBDI)Mg−Mg(DIPPBDI) 55.8 kcal mol−1). Natural-Population-Analysis (NPA) shows fragment charges: (DIPePBDI*)Mg +0.27/BeCp* −0.27. The very low NPA charge on Be (+0.62) compared to Mg (+1.21) and the strongly upfield 9Be NMR signal at −23.7 ppm are in line with considerable electron density on Be and the formal oxidation state assignment of MgII−Be0. Despite this Mgδ+−Beδ− polarity, 1 is extremely thermally stable and unreactive towards H2, CO, N2, cyclohexene and carbodiimide. It reacted with benzophenone, azobenzene, phenyl acetylene, CO2 and CS2. Reaction with 1-adamantyl azide led to reductive coupling and formation of an N6-chain. The azide reagent also inserted in the Cp*−Be bond. The inertness of 1 is likely due to bulky ligands protecting the Mg−Be unit.

Authors with CRIS profile

Johannes Maurer Lehrstuhl für Anorganische und Metallorganische Chemie Lukas Klerner Lehrstuhl für Anorganische und Metallorganische Chemie Sjoerd Harder Lehrstuhl für Anorganische und Metallorganische Chemie

Involved external institutions

Philipps-Universität Marburg DE Germany (DE)

How to cite

APA:

Berthold, C., Maurer, J., Klerner, L., Harder, S., & Buchner, M.R. (2024). Formation, Structure and Reactivity of a Beryllium(0) Complex with Mgδ+−Beδ− Bond Polarization. Angewandte Chemie International Edition. https://doi.org/10.1002/anie.202408422

MLA:

Berthold, Chantsalmaa, et al. "Formation, Structure and Reactivity of a Beryllium(0) Complex with Mgδ+−Beδ− Bond Polarization." Angewandte Chemie International Edition (2024).

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