X‐ray Crystallography of Organogermanium Compounds

Hemmert, Catherine

doi:10.1002/9781119613466.ch16

“…The 13 C NMR data (( δ 13 C(C1/4)=150.2, δ 13 C(C2/3)=161.5) and the metrics of the germole ring (C1−C2, C3−C4=135 pm; C2−C3=149 pm) are characteristic for disubstituted germoles and indicate a localized butadiene system (see the Tables S2 and S6 for further details) [66–67] . Despite the large substituents, the Ge−Al bonds in germole 12 e are among the shortest reported so far (Al−Ge=247 pm vs. 245–256 pm from a recent literature survey [68–70] and 247 pm based on covalent radii derived from quantum mechanical calculations) [46] …”

Section: Resultsmentioning

confidence: 99%

“…The 13 S2 and S6 for further details). [66][67] Despite the large substituents, the GeÀ Al bonds in germole 12 e are among the shortest reported so far (AlÀ Ge = 247 pm vs. 245-256 pm from a recent literature survey [68][69][70] and 247 pm based on covalent radii derived from quantum mechanical calculations). [46] In the case of the reaction of the bis(trimethylsilyl)amino-substituted aluminum dichloride 5 f with K 2 [1], the germanium alumole complex 3 f was always obtained as an approx.…”

Section: Methodsmentioning

confidence: 96%

Aluminagerma[5]pyramidanes—Formation and Skeletal Rearrangement

Bührmann,

Albers,

Beuße

et al. 2024

Angew Chem Int Ed

0

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The salt metathesis reaction of dipotassium germacyclopentadienediide with aluminum(III) dichlorides provides either half‐sandwich alumole complexes of germanium(II) or aluminylene germole complexes. Their molecular structure and the delocalized bonding situation, revealed by density functional theory (DFT) calculations, are equally described as isomeric aluminagerma[5]pyramidanes with either the germanium or the aluminum atom in the apical position of the pentagonal pyramid. The product formation and the selectivity of the reaction depends on the third substituent of the aluminum dichloride. Aryl‐substituents favor the formation of alumole complexes and Cp*‐substituents that of the isomeric germole complexes. With amino‐substituents at the aluminum atom mixtures of both isomers are formed and the positional exchange of the two heteroatoms is shown by NMR spectroscopy. The alumole complexes of Ge(II) undergo facile reductive elimination of germanium and form the corresponding alumoles.

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“…Die 13 C NMR-Daten (δ 13 C(C1/4) = 150.2, δ 13 C(C2/3) = 161.5) und die Metrik des Germolrings (C1À C2, C3À C4 = 135 pm; C2À C3 = 149 pm) sind charakteristisch für disubstituierte Germole und deuten auf ein lokalisiertes Butadiensystem hin (siehe Tabellen S2 und S6 für weitere Details). [66][67] Trotz der großen Substituenten gehören die GeÀ Al-Bindungen in Germol 12 e zu den kürzesten, über die bisher berichtet wurde (AlÀ Ge = 247 pm gegenüber 245-256 pm aus einer aktuellen Literaturübersicht [68][69][70] und 247 pm auf der Grundlage von aus quantenmechanischen Berechnungen abgeleiteten kovalenten Radien). [46] Bei der Reaktion des bis(trimethylsilyl)aminosubstituierten Aluminiumdichlorids 5 f mit K 2 [1] wurde der Germanium-Alumolkomplex 3 f immer als ca.…”

Section: Methodsunclassified

Aluminagerma[5]pyramidane – Bildung und Gerüstumlagerung

Bührmann,

Albers,

Beuße

et al. 2024

Angewandte Chemie

0

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The salt metathesis reaction of dipotassium germacyclopentadienediide with aluminum(III) dichlorides provides either half‐sandwich alumole complexes of germanium(II) or aluminylene germole complexes. Their molecular structure and the delocalized bonding situation, revealed by density functional theory (DFT) calculations, are equally described as isomeric aluminagerma[5]pyramidanes with either the germanium or the aluminum atom in the apical position of the pentagonal pyramid. The product formation and the selectivity of the reaction depends on the third substituent of the aluminum dichloride. Aryl‐substituents favor the formation of alumole complexes and Cp*‐substituents that of the isomeric germole complexes. With amino‐substituents at the aluminum atom mixtures of both isomers are formed and the positional exchange of the two heteroatoms is shown by NMR spectroscopy. The alumole complexes of Ge(II) undergo facile reductive elimination of germanium and form the corresponding alumoles.

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Germaaluminocene – Maskierte Heterofulvene

Geibel,

Bührmann,

Albers

et al. 2024

Angewandte Chemie

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Germaaluminocenes are formed by salt metathesis reactions of dipotassium germacyclopentadienediides with cyclopentadienylaluminum dichloride. The reactivity pattern of these sandwich complexes is determined by the electrophilic central aluminum atom and by the nucleophilic dicoordinated germanium center. Surprisingly, the products formed by reactions with Lewis acids, Lewis bases, amphiphiles and compounds with polar double bonds are those expected from the reaction of a hypothetical aluminagermapentafulvene with these types of reagents. This suggests that germaaluminocenes are synthetic equivalents to these pentafulvenes.

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X‐ray Crystallography of Organogermanium Compounds

Cited by 5 publications

References 659 publications

Aluminagerma[5]pyramidanes—Formation and Skeletal Rearrangement

Aluminagerma[5]pyramidanes—Formation and Skeletal Rearrangement

Aluminagerma[5]pyramidane – Bildung und Gerüstumlagerung

Germaaluminocene – Maskierte Heterofulvene

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