Lithiierte Phosphanimin‐Komplexe. Die Kristallstrukturen von [LiCH(Me)PEt2NSiMe3]4 und des Cuprats [Li{Me3SiNPMe2CH2–Cu–CH(SiMe2OLi)PMe2NSiMe3}]2

Lithiated Phosphoraneimine Complexes. Crystal Structures of [LiCH(Me)PEt₂NSiMe₃]₄ and of Cuprate [Li{Me₃SiNPMe₂CH₂–Cu–CH(SiMe₂OLi)PMe₂NSiMe₃}]₂ [LiCH(Me)PEt₂NSiMe₃]₄ ( 1 ) has been obtained as colorless, oxygen and moisture sensitive crystals from the reaction of the silylated phosphoraneimine Me₃SiNPEt₃ with ⁿbutyllithium in ⁿhexane at 0 °C. 1 crystallizes in the tetragonal space group I4₁/acd with eight formula units per unit cell. Lattice dimensions at –80 °C: a = b = 1505.2(1), c = 4747.4(6) pm, R₁ = 0.0278. 1 forms a Li₄ tetrahedron, the faces of which are capped with the carbon atoms of the carbanionic ‐CH(Me)‐ groups. The nitrogen atoms occupy the corners of the Li₄ tetrahedron by means of “inner solvation”. The cuprate [Li{Me₃SiNPMe₂CH₂–Cu–CH(SiMe₂OLi)PMe₂NSiMe₃}]₂ ( 4 ) has been obtained from the known [LiCH₂PMe₂NSiMe₃]₄ and copper(I) iodide in the presence of silicon grease (‐OSiMe₂‐)_n in diethylether, forming colorless oxygen and moisture sensitive crystals. 4 crystallizes in the triclinic space group P 1 with one formula unit per unit cell. Lattice dimensions at –50 °C: a = 1025.4(2), b = 1145.5(2), c = 1261.0(2) pm, α = 65.19(1)°, β = 79.55(1)°, γ = 77.94(1)°, R₁ = 0.039. 4 forms a centrosymmetric dimeric molecule with a central Li₂O₂ four‐membered ring, the oxygen atoms of which are connected by ‐SiMe₂‐ bridges with the cuprate fragment > CH–Cu–CH₂‐.     

[Li7(CHPMe2NSiMe3)3(OSiMe2nBu)]2, ein Gemischtligand-Li14-Cluster mit dem Carbdianion (CHPMe2NSiMe3)2−

[Li₇(CHPMe₂NSiMe₃)₃(OSiMe₂ⁿBu)]₂, a Mixed-Ligand-Li₁₄ Cluster with the Carbdianion (CHPMe₂NSiMe₃)^2? The title compound is formed as colourless moisture and oxygen sensitive crystals by the reaction of [LiCH₂PMe₂NSiMe₃]₄ with zinc or cobalt chloride in a toluene suspension in the presence of silicongrease (–OSiMe₂–)_n and n-butyllithium. It is characterized by multinucleus NMR spectroscopy and by crystal structure determinations of two different crystal individuals. 1. Space group P1 , Z = 1, lattice dimensions at ?70 °C: a = 1272.0, b = 1392.6, c = 1417.6 pm, α = 115.33°, β = 96.75°, σ = 106.81°; R = 0.042. 2. Space group P2₁/n, Z = 2, lattice dimensions at ?50 °C: a = 1424.8, b = 1457.1, c = 1997.0 pm, β = 90.32, R = 0.069.     

[Me3Si(CF3)F]− and [Me3Si(CF3)2]−: Reactive Intermediates in Fluoride-Initiated Trifluoromethylation with Me3SiCF3— An NMR Study

The long-postulated reactive intermediates of polar fluoride-inititated trifluoromethylations with Me₃SiCF₃ (see scheme) were identified by NMR spectroscopy as [Me₃Si(CF₃)F]⁻ and [Me₃Si(CF₃)₂]⁻_.     

Das iso-Tetraphosphan P[P(SiMe3)Me]2[P(SiMe3)2]

H ? C Bond Cleavage in Ferrocene by Organylruthenium Complexes Cp*(Me₃P)₂RuCH₂CMe₃ ( 1 ) reacts at 85°C with ferrocene ( 2 ) by cleavage of one H? C bond in 2 to give CpFe[η⁵-C₅H₄Ru(PMe₃)₂Cp*] ( 3 ) (Cp = η⁵-C₅H₅; Cp* = η⁵-C₅Me₅) and neopentane. The ruthenium atom in 3 has a distorted tetrahedral geometry, the planar Cp ligands in the ferrocenyl fragment are eclipsed. Solutions of 3 in [D₆]benzene or [D₈]THF exhibit H? D exchange of the ferrocenyl protons. In the [D₈]THF molecule only the α-deuterium atoms are exchanged. Reaction pathways for this exchange are discussed.     

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

Reactions of Zn^I₂L₂ (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 {[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⁻.