Synthesis of (Ge₉–Ge₉)^6– Dimeric Zintl Ions in Liquid Ammonia Solutions of K₄Ge₉: Low‐Dimensional Coordination Networks in the Crystal Structure of the Ammoniates K<i>_n</i>[K([2.2.2]crypt)]_6–<i>n</i>[Ge₉–Ge₉](NH₃)<i>_m</i> (<i>n</i> = 2, 3, and 4)

Abstract

Abstract Three new compounds of the dimeric cluster anion [Ge 9 –Ge 9 ] 6– were obtained from liquid ammonia solutions of the Zintl phase K 4 Ge 9 . All of them follow the general formula K n [K([2.2.2]crypt)] 6– n [Ge 9 –Ge 9 ](NH 3 ) m ( 1 : n = 4, m = 14; 2 : n = 3, m = 18; 3 : n = 2, m = 17.28) and comprise sequestered and non‐sequestered K + cations in different ratios. The non‐sequestered cations coordinate to the Ge 9 cages and support the covalent intercluster bond. Additionally, they are in contact with each other by varying numbers of coordinative ammonia bridges leading to arrangement of the anions. The dimensionality of the cluster arrangements correlates with the amount of sequestering molecules. Layers, double chains and single chains are observed for 1 , 2 , and 3 , respectively, according to an increase of [2.2.2]crypt) per formula unit for 1 to 3 .