Retention of the Zn−Zn bond in [Ge9Zn−ZnGe9]6− and Formation of [(Ge9Zn)−(Ge9)−(ZnGe9)]8− and Polymeric 1∞ [−(Ge9Zn)2−−]1

Reactions of ZnI2L2 (where L=[HC(PPh2NPh)]−) with solutions of the Zintl phase K4Ge9 in liquid ammonia lead to retention of the Zn−Zn bond and formation of the anion [(η4-Ge9)Zn−Zn(η4-Ge9)]6−, representing the first complex with a Zn−Zn unit carrying two cluster entities. The trimeric anion [(η4-Ge9)Zn{μ2(η1:η1Ge9)}Zn(η4-Ge9)]8− forms as a side product, indicating that oxidation reactions also take place. The reaction of Zn2Cp*2 (Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) with K4Ge9 in ethylenediamine yielded the linear polymeric unit 1∞ {[Zn[μ2(η4:η1Ge9)]}2− with the first head-to-tail arrangement of ten-atom closo-clusters. All anions were obtained and structurally characterized as [A(2.2.2-crypt)]+ salts (A=K, Rb). Copious computational analyses at a DFT-PBE0/def2-TZVPP/PCM level of theory confirm the experimental structures and support the stability of the two hypothetical ten vertex cluster fragments closo-[Ge9Zn]2− and (paramagnetic) [Ge9Zn]3−.