Synthesis and Crystal Structures of the Polygermanide Ammoniates K₄Ge₉×9NH₃, Rb₄Ge₉×5NH₃ and Cs₆Ge₁₈×4NH₃.

Abstract

Germanium I 4700 Synthesis and Crystal Structures of the Polygermanide Ammoniates K 4 Ge 9 ·9NH 3 , Rb4Ge9·5NH3 and Cs6Ge18·4NH3. -The structures of the new polygermanides (III) (orthorhombic, space group Pnma, Z = 4), (V) (monoclinic, P21/c, Z = 4), and (VII) (monoclinic, P21/n, Z = 2) are determined by low-temperature (123 K) XRD. -(SUCHENTRUNK, C.; DANIELS, J.; SOMER, M.; CARRILLO-CABRERA, W.; KORBER*, N.; Z. Naturforsch., B: Chem. Sci. 60 (2005) 3, 277-283; Inst. Anorg. Chem., Univ. Regensburg, D-93053 Regensburg, Germany; Eng.) -Schramke 23-018

Chemistry of Deltahedral Zintl Ions

“…These ideas were further supported by the subsequent synthesis of a dimer of Ge 9 clusters, [Ge 9 −Ge 9 ] 6- (Figure ) …”

“…The dimer was synthesized by reducing even further the amount of 2,2,2-crypt to about a third of that needed for complete sequestering of the alkali-metal cations. The larger amount of available naked cations stabilizes the dimer in the crystalline [K(2,2,2-crypt)] 2 K 4 [Ge 9 −Ge 9 ] 16b. Use of other sequestering agents in insufficient amounts also yields the dimeric species, as seen in [Rb(benzo-18-crown-6)] 2 Rb 4 [Ge 9 −Ge 9 ] and [K(18-crown-6)] 2 K 4 [Ge 9 −Ge 9 ] 16b.…”

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 Kn[K([2.2.2]crypt)]6–n[Ge9–Ge9](NH3)m (n = 2, 3, and 4)

“…They discovered several compounds of [Ge 9 ] x – ( x = 3, 4) clusters and different [ A ( L )] + ( A = K, Rb, Cs; L = 18crown‐6, [2.2.2]crypt) as well as the D 3 h symmetric closo ‐cluster [Ge 5 ] 2– . [11,26] Furthermore, a dimeric anion [Ge 9 –Ge 9 ] 6– was found in Cs 6 [Ge 9 –Ge 9 ](NH 3 ) 4 11. In this solid compound the anion‐cation interactions abound and lead to the formation of a three‐dimensional network characterized by short Ge–Cs and Cs–Cs distances.…”

“…They can be described with 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 differ in the number of solvent molecules per formula unit as well as in the ratio of sequestered to non‐sequestered potassium atoms. In contrast to an earlier report on the formation of a dimer in liquid ammonia solutions without using oxidizing agents and formation of a three‐dimensional network in Cs 6 [Ge 9 –Ge 9 ](NH 3 ) 4 ,11 we report here on low‐dimensional coordination networks of Ge 9 –Ge 9 dimers. Since an isomer of a [Ge 9 –Ge 9 ] 6– anion with a different structure than the cisoid conformers had been reported before,10 we investigated here the crystal structures of the dimers in the novel compounds 1 to 3 .…”

[As7M(CO)3]3– M = Cr, Mo, W: Bonding and Electronic Structure of Cluster Assemblies with Metal Carbonyls

“…The crypt molecule (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane) encapsulates the potassium ion and its large size reduces the dimensionality of the ionically linked assembly, whereas the Cs atom is too large to be cryptated and ionically links the clusters. Zintl clusters may also be covalently linked to form assemblies of interest including homoatomic clusters linked by heteroatoms. − Zintl clusters can be functionalized by main group organometallic compounds and early transition-metal organometallics. − Most recently, organo-Zintl clusters have been synthesized. − The control over architecture possible with Zintl phases makes them prototypes for understanding the interplay of interactions between clusters with their linkers, and the global properties of the cluster assembly.…”