Nonagermanide Zintl Clusters with Mg²⁺ Counter Ions

Abstract

Dedicated to Professor Cameron Jones on the Occasion of his 60 th Birthday.Ion exchange processes are rarely investigated with respect to tetrel element Zintl clusters. We now discovered that the addition of Mg complexes to nonagermanide anions comprising K + counter cations results in an exchange of the alkali ions by alkaline earth cations. Upon stirring K[Ge 9 {Si(TMS) 3 } 3 ] (TMS = trimethylsilyl) and Mg(NacNac Mes )I (NacNac Mes = N,N '-bis(2,4,6trimethylphenyl)-β-diketiminate) in MeCN the product [Mg(NacNac Mes )(MeCN) 4 ][Ge 9 {Si(TMS) 3 } 3 ]• MeCN is formed. Reactions of Mg(NacNac Mes )I with K 4 Ge 9 in liquid ammonia as a solvent yielded [K[2.2.2]crypt] 4 [Mg(NacNac Mes )(NH 3 ) 4 ] 2 [Ge 9 À Ge 9 ] • 32.58 NH 3 featuring a mixed alkali/alkaline earth metal cationic sphere and an oxidative coupling of the [Ge 9 ] 4À clusters. From comparable reactions of [Mg(NacNac Mes )] 2 with K 4 Ge 9 or K 12 Ge 17 in liquid ammonia crystals of [K-[2.2.2]crypt][NacNac Mes ] • NH 3 and [K(18-crown-6)][NacNac Mes ] • 3 NH 3 , respectively, were isolated. All compounds were characterized by means of single crystal structure determination.