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

Abstract

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 0pt2.84526pt12.84526pt∞ {[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−.

Synthesis and Structures of s- and p-Block Metal Complexes Containing Sterically Demanding Pentaarylcyclopentadienyl Substituents

“…Our long-term interest in the synthesis and reactivity of low-valent organometallic reagents such as Cp*Al, Cp*Ga, and Cp* 2 Zn 2 , which has only recently resulted in the stabilization of unusual bonding situations such as stable metal-centered radicals or π-bonded complexes, − prompted our attention toward the synthesis of sterically more demanding pentaarylcyclopentadienyl ligands (Cp Big p -Alk ), which are expected to kinetically stabilize the corresponding (low-valent) metal complexes. Moreover, they may also be applied in the synthesis of metal-centered radicals, which are accessible after homolytic metal–Cp bond breakage, as well as of cluster-type metal complexes, which may be formed by oligomerization of metal-centered radicals.…”

Orientational Isomerism and Its Reactivity of a Main Group Sandwich Anion [Ge9‐In‐Ge9]5–

“…The model is similar but different from the related cases of heavy Tl(I) coordinated by E 9 , [Ni@E 9 ] unit (E = Ge/Sn) and Ge 9 (Hyp) 3 – (Hyp = Si(SiMe 3 ) 3 ) as stable closo ‐species. [ 55‐56 ] In addition, besides the mono‐valent Zn/Cd complexes based on Ge/Pb‐cluster scaffolds, [ 47,57 ] a similar situation was also observed in another cluster species {(Ge 9 ) 2 [ η 6 ‐Ge(PdPPh 3 ) 3 ]} 4– where a zero‐valent germanium core in the sp 2 ‐GePd 3 fragment was stabilized by two Ge 9 ligands. [ 49 ] Thus, the Ge 9 unit is potential to act as a supporting donor ligand like NHC towards low‐valent main group elements.…”

“…[ 34‐38 ] Similar situation was also common in the heavier Sn or Pb clusters. [ 39‐45 ] In contrast, the coordination assembly of Ge 9 units and TMs (or main group metals) has constructed a series of new heterometallic clusters, especially for the sandwich‐type species like [Ge 9 ‐Au 3 ‐Ge 9 ] 5– , [Ge 9 Zn‐ZnGe 9 ] 6– , [Ge 9 ‐In‐Ge 9 ] 5– and {(Ge 9 ) 2 [ η 6 ‐Ge(PdPPh 3 ) 3 ]} 4– , [ 46‐49 ] similar to the other all‐inorganic [Sb 3 ‐Au 3 ‐Sb 3 ] 3– and [(P 5 ) 2 Ti] 2– . [ 50‐51 ] These inorganic sandwich compounds have further expanded the boundaries of cyclic π ligands and metal centers compared with the ferrocene (C 5 H 5 ) 2 Fe.…”

Bridging Aromatic/Antiaromatic Units: Recent Advances in Aromaticity and Antiaromaticity in Main‐Group and Transition‐Metal Clusters from Bonding and Magnetic Analyses

“…Moreover, in literature there are other interesting examples of dimers of clusters, highlighting {[CuSn 5 Sb 3 ] 2− } 2 [144] as an aggregate of inhomogeneous superatoms, suggesting the presence of aromatic building blocks. Other examples of group 14 and 15 clusters aggregates [145–151] expose the formation of covalently connected dimers, trimers and extended chains, [152] where the theoretical identification of spherical aromatic units benefits the rational obtention of cluster‐assembled materials. Thus, concepts of aromaticity are useful in the choice of stable building blocks expected to retrain their individual properties in an extended aggregate.…”