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Idiosyncratic Ag 7 Pt 2 O 7 : An Electron Imprecise yet Diamagnetic Small Band Gap Oxide
Author(s) -
Thakur Gohil S.,
Dinnebier Robert,
Hansen Thomas C.,
Assenmacher Wilfried,
Felser Claudia,
Jansen Martin
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202008874
Subject(s) - valence electron , substructure , platinum , chemical bond , chemistry , oxide , crystal chemistry , valence (chemistry) , crystallography , electron , electron counting , diamagnetism , band gap , crystal structure , inorganic chemistry , condensed matter physics , physics , quantum mechanics , biochemistry , structural engineering , organic chemistry , magnetic field , engineering , catalysis
The seminal qualitative concepts of chemical bonding, as presented by Walter Kossel and Gilbert Newton Lewis back in 1916, have lasting general validity. These basic rules of chemical valence still serve as a touchstone for validating the plausibility of composition and constitution of a given chemical compound. We report on Ag 7 Pt 2 O 7 , with a composition that violates the basic rules of chemical valence and an exotic crystal structure. The first coordination sphere of platinum is characteristic of tetravalent platinum. Thus, the electron count corresponds to Ag 7 Pt 2 O 7 *e − , where excess electrons are associated with the silver substructure. Such conditions given, it is commonly assumed that the excess electrons are either itinerant or localized in Ag−Ag bonds. However, the material does not show metallic conductivity, nor does the structure feature Ag‐Ag pairs. Instead, the excess electrons organize themselves in 2e−4c bonds within the silver substructure. This subvalent silver oxide reveals a new general facet pertinent to silver chemistry.