アイテム詳細

要旨

The Zintl phase K2BaSi4 has been synthesized from the mixture of precursors KSi and BaSi2. The crystal structure of K2BaSi4 was elucidated from X-ray powder diffraction data: Pearson symbol oP28, space group Pbcm, a=9.4950(1), b=9.2392(1), c=9.9025(1) Å. The main building block of the crystal structure are tetrahedral anions Si44–. Analysis of chemical bonding for K2BaSi4 and its chemical analogs – molecular H4Si4 and solid state K4Si4 employing the electron localizability approach reveals the basic agreement with the Zintl model in terms of number of basins for Si−Si bonds and lone pairs at Si atoms, as well as the charge transfer direction. The populations of the bond and ‘lone-pair’ basins agree with the Zintl count for molecular species and deviate strongly for the solids, in particular, while the ‘lone-pair’ basins are over-populated, the bond basins are essentially under-populated. The topology of the calculated electron density and electron-localizability indicator is very sensitive toward the interatomic distances and angles in the Si44− anion. © 2023 The Authors. Zeitschrift für anorganische und allgemeine Chemie published by Wiley-VCH GmbH.