Synthesis and Structural Characterization of the New Clathrates K₈Cd₄Ge42, Rb₈Cd₄Ge42, and Cs₈Cd₄Ge42

Marion C Schäfer; Svilen Bobev

doi:10.3390/ma9040236

Synthesis and Structural Characterization of the New Clathrates K₈Cd₄Ge₄₂, Rb₈Cd₄Ge₄₂, and Cs₈Cd₄Ge₄₂

Materials (Basel). 2016 Mar 25;9(4):236. doi: 10.3390/ma9040236.

Authors

Marion C Schäfer¹, Svilen Bobev²

Affiliations

¹ Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. schaefer@udel.edu.
² Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. bobev@udel.edu.

Abstract

This paper presents results from our exploratory work in the systems K-Cd-Ge, Rb-Cd-Ge, and Cs-Cd-Ge, which yielded the novel type-I clathrates with refined compositions K₈Cd_3.77(7)Ge_42.23, Rb₈Cd_3.65(7)Ge_42.35, and Cs_7.80(1)Cd_3.65(6)Ge_42.35. The three compounds represent rare examples of clathrates of germanium with the alkali metals, where a d¹⁰ element substitutes a group 14 element. The three structures, established by single-crystal X-ray diffraction, indicate that the framework-building Ge atoms are randomly substituted by Cd atoms on only one of the three possible crystallographic sites. This and several other details of the crystal chemistry are elaborated.

Keywords: Zintl phases; cadmium; clathrates; germanium; type-I structure.