Yet Another Case of Lithium Metal Atoms and Germanium Atoms Sharing Chemistry in the Solid State: Synthesis and Structural Characterization of Ba2LiGe3
Date
2023-12-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Chemistry - A European Journal
Abstract
Several Ba−Li−Ge ternary phases are known and structurally characterized, including the title compound Ba2LiGe3. Its structure is reported to contain [Ge6]10− anions that exhibit delocalized bonding with a Hückel-like aromatic character. The Ge atoms are in the same plane with the Li atoms, and if both types of atoms are considered as covalently bonded, [LiGe3]4− honeycomb-like layers will result. The latter are separated by slabs of Ba2+ cations. However, based on the systematic work detailed herein, it is necessary to re-evaluate the phase as Ba2Li1−xGe3+x (x<0.05). Although small, the homogeneity range is clearly demonstrated in the gradual change of the unit cell for four independent samples. Subsequent characterization by single-crystal X-ray diffraction methods shows that the Ba2Li1−xGe3+x structure, responds to the varied number of valence electrons and the changes are most pronounced for the refined lengths of the Li−Ge and Ge−Ge bonds. Indirectly, the changes in the Ge−Li/Ge distances within layers affect the stacking too, and these changes can be correlated to the variation of the c-cell parameter. Chemical bonding analysis based on TB-LMTO-ASA level calculations affirms the notion for covalent character of the Ge−Ge bonds; the Ba−Ge and Li−Ge interactions also show some degree of covalency.
Graphical Abstract available at: https://doi.org/10.1002/chem.202302385
The structure of Ba2Li1−xGe3+x, emphasizing the honeycomb-like [Li1−xGe3+x] layers with Li and Ge atoms (denoted in blue and gold) in a partially disordered state.
Description
This is the peer reviewed version of the following article: K. Ghosh, S. Bobev, Chem. Eur. J. 2023, 29, e202302385., which has been published in final form at https://doi.org/10.1002/chem.202302385. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited. © 2023 Wiley-VCH GmbH. This article will be embargoed until 12/06/2024.
Keywords
crystal structure, germanium, lithium, Zintl phases
Citation
K. Ghosh, S. Bobev, Chem. Eur. J. 2023, 29, e202302385.