Synthesis And Crystal Structures Of The Polygermanide Ammoniates K₄Ge₉ · 9 NH₃, Rb₄Ge₉ · 5 NH₃ And Cs₆Ge₁₈ · 4 NH₃

Abstract

The new compounds K4Ge9 ·9 NH3 and Rb4Ge9 ·5 NH3 were prepared by the extraction of K4Ge9 and Rb4Ge9 with liquid ammonia and characterized by low temperature X-ray structure analysis. They both contain monocapped square antiprismatic Ge94− anions. Cs6Ge18 ·4 NH3 was prepared by the extraction of K2Cs2Ge9 with liquid ammonia in the presence of [(Bu)3MeN](Br2I) as an oxidizing agent, and contains a [Ge9-Ge9]6− dimer in which two Ge94− anions are linked by a single Ge-Ge bond

Crystal Structure of the Protonated Germanide Cluster [HGe9]3−

“…The average atomic distance (d) has a value of 2.637 Å. This is in good accordance with previously reported germanide clusters [16,18]. The longest Ge-Ge bond lengths can be found in the central square plane (Ge5-Ge6, Ge5-Ge8, Ge6-Ge7, Ge7-Ge8, Table 2).…”

“…This changed after the introduction of the chelating alkali metal ligand cryptand to these solutions by Corbett [4,5], when the isolation and structural characterization of solvate structures containing Zintl anions was facilitated. At present, for group 14 elements the representative homoatomic cluster anions identified in several solid state and solvate structures are [E 4 ] 4− (E = Si-Pb) [6][7][8][9], [E 5 ] 2− (E = Si-Pb) [10][11][12][13], [E 9 ] x− (x = 4; E = Si-Pb; x = 3, E = Si-Sn; x = 2 E = Si,Ge) [5,[14][15][16][17][18] and [E 10 ] 2− (E = Ge, Pb) [19,20]. For solvation experiments with germanium clusters, A 4 Ge 9 (A = K-Cs) [21,22] or A 12 Ge 17 (A = Na, K, K/Rb, Rb, Cs) [23,24] phases are used as starting materials, which contain the nine-atom germanide cluster or respectively [Ge 9 ] 4− /[Ge 4 ] 4− cage anions in a ratio of 1:2.…”

“…[ (1)) [31]. An oxidation state of −3 or −2 per [Ge 9 ] cage can also be observed in dimers [Ge 9 -Ge 9 ] 6− [16,33,34], trimers [Ge 9 =Ge 9 =Ge 9 ] 6− [35,36], tetramers [Ge 9 =Ge 9 =Ge 9 =Ge 9 ] 8− [37,38] or in one-dimensionally extended 1 ∞ [-Ge 9 -] 2− [39-41] chains, which could be obtained by the oxidative coupling of [Ge 9 ] 4− anions. However, the protonation of [Ge 9 ] 4− clusters is also highly likely (Equation (2)).…”

Silicon Containing Nine Atom Clusters from Liquid Ammonia Solution: Crystal Structures of the First Protonated Clusters [HSi9]3– and [H2{Si/Ge}9]2–

“…The sequestering agents, although present in notable amount in solution, are not part of the crystallized solid, and crystallization of the simple ammoniate seems to be favored. This is supported by the finding of the isotypic compound K 4 [Si 5.6 Ge 3.4 ] · 9NH 3 ( 2 ) after replacing the pure Si containing Zintl precursor by K 12 Si 8 Ge 9 , and also the pure Ge compound is known …”

Heteroatomic Si/Ge Zintl Clusters: Single‐Crystal Structure Determination of Rb4[Si7.8Ge1.2](NH3)5 and [Rb([18]crown‐6)Rb3][Si7.5Ge1.5](NH3)4

“…0.1 Å) compared to [Ge 9 ] 4− 30. 36 Given that in 1 a only 34 % of the atomic positions 1–4 are occupied by Ge, a slight enlargement of the diagonals d 1 and d 2 in 1 a is noticeable, as described above. However, a strong elongation of the corresponding displacement vectors for the atoms at position 1–4 cannot be expected (Figure 1).…”