Reaction of aryl azides with tris(trimethylsilyl)silyllithium: Synthesis of tmeda or thf adducts of [Li{N(Ar)Si(SiMe3)3}] and 1,4-trimethylsilyl migration from oxygen to nitrogen

Reaction of ArN₃ (Ar = Ph, p-MeC₆H₄, 1-naphthyl) with [Li{Si(SiMe₃)₃}(thf)₃] yielded lithium amides [Li{N(Ar)Si(SiMe₃)₃}L] (L = tmeda or (thf)₂). Similar treatment of o-phenylene diazide with 2 equiv. of [Li{Si(SiMe₃)₃}(thf)₃] formed dilithium diamide complex 4. Reaction between o-Me₃SiOC₆H₄N₃ and [Li{Si(SiMe₃)₃}(thf)₃] afforded, via 1,4-trimethylsilyl migration from oxygen to nitrogen, [Li{OC₆H₄{N(SiMe₃)Si(SiMe₃)₃}-2}]₂ (5). The structures of complexes 3 and 5 have been determined by single crystal X-ray diffraction techniques.     

Neue metallorganisch substituierte Indium–Stickstoff-Verbindungen. Synthese und Kristallstrukturen von [{Cp(CO)3Mo}2InN(SiMe3)2] und [{Cp(CO)3Mo}In{N(SiMe3)2}2]

New Organometallic Indium Nitrogen Compounds. Synthesis and Crystal Structures of [{Cp(CO)₃Mo}₂InN(SiMe₃)₂] and [{Cp(CO)₃Mo}In{N(SiMe₃)₂}₂] The reaction of [{Cp(CO)₃Mo}₂InCl] with LiN · (SiMe₃)₂ leads to the formation of [{Cp(CO)₃Mo}₂InN · (SiMe₃)₂] ( 1 ). 1 is monomeric and it contains an indium atom which is coordinated in a trigonal planar manner by two {Cp(CO)₃Mo} fragments and a N(SiMe₃)₂ group. The corresponding bis-amide [{Cp(CO)₃Mo}In{N(SiMe₃)₂}₂] ( 2 ) is prepared by the reaction of [{Cp(CO)₃Mo}InCl₂] with two equivalents of LiN(SiMe₃)₂. In analogy to 1, 2 is monomeric and it contains an indium atom in a trigonal planar coordination.     

Cerium(III/IV) Formamidinate Chemistry,and a Stable Cerium(IV) Diolate

Four new cerium(III) formamidinate complexes comprising [Ce(p‐TolForm)₃], [Ce(DFForm)₃(thf)₂], [Ce(DFForm)₃], and [Ce(EtForm)₃] were synthesized by protonolysis reactions using [Ce{N(SiMe₃)₂}₃] and formamidines of varying functionality, namely N,N′‐bis(4‐methylphenyl)formamidine (p‐TolFormH), N,N′‐bis(2,6‐difluorophenyl)formamidine (DFFormH), and the sterically more demanding N,N′‐bis(2,6‐diethylphenyl)formamidine (EtFormH). The bimetallic cerium lithium complex [LiCe(DFForm)₄] was synthesized by treating a mixture of [Ce{N(SiHMe₂)₂}₃(thf)₂] and [Li{N(SiHMe₂)₂}] with four equivalents of DFFormH in toluene. Oxidation of the trivalent cerium(III) formamidinate complexes by trityl chloride (Ph₃CCl) caused dramatic color changes, although the cerium(IV) species appeared transient and reformed cerium(III) complexes and N′‐trityl‐N,N′‐diarylformamidines shortly after oxidation. The first structurally characterized homoleptic cerium(IV) formamidinate complex [Ce(p‐TolForm)₄] was obtained through a protonolysis reaction between [Ce{N(SiHMe₂)₂}₄] and four equivalents of p‐TolFormH. [Ce{N(SiHMe₂)₂}₄] was also treated with DFFormH and EtFormH, but the resulting cerium(IV) complexes decomposed before isolation was possible. The new cerium(IV) silylamide complex [Ce{N(SiMe₃)₂}₃(bda)_0.5]₂ (bda=1,4‐benzenediolato) was synthesized by treatment of [Ce{N(SiMe₃)₂}₃] with half an equivalent of 1,4‐benzoquinone, and showed remarkable resistance towards protonolysis or reduction.     

Komplexchemie P‐reicher Phosphane und Silylphosphane. XXII. Die Bildung von [η2‐{tBu–P=P–SiMe3}Pt(PR3)2]aus (Me3Si)tBuP–P=P(Me)tBu2 und [η2‐{C2H4}Pt(PR3)2]

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XXII. The Formation of [η²‐{^tBu–P=P–SiMe₃}Pt(PR₃)₂] from (Me₃Si)^tBuP–P=P(Me)^tBu₂ and [η²‐{C₂H₄}Pt(PR₃)₂] (Me₃Si)^tBuP–P = P(Me)^tBu₂ reacts with [η²‐{C₂H₄}Pt(PR₃)₂] yielding [η²‐{^tBu–P=P–SiMe₃}Pt(PR₃)₂]. However, there is no indication for an isomer which would be the analogue to the well known [η²‐{^tBu₂P–P}Pt(PPh₃)₂]. The syntheses and NMR data of [η²‐{^tBu–P=P–SiMe₃}Pt(PPh₃)₂] and [η²‐{^tBu–P=P–SiMe₃}Pt(PMe₃)₂] as well as the results of the single crystal structure determination of [η²‐{^tBu–P=P–SiMe₃}Pt(PPh₃)₂] are reported.     

Reaktionen von Zink- und Cadmiumhalogeniden mit Tris(trimethylsilyl)phosphan und Tris(trimethylsilyl)arsan

Reactions of Zinc and Cadmium Halides with Tris(trimethylsilyl)phosphane and Tris(trimethylsilyl)arsane ZnCl₂ reacts with E(SiMe₃)₃ (E = P, As) in toluene in the presence of PⁿPr₃ to give the binuclear complexes [Zn₂Cl₂{E(SiMe₃)₂}₂(PⁿPr₃)₂] · C₇H₈ (E = P 1 , As 2 ). Therefore by the use of PⁱPr₃ clusters consisting of ten metal atoms are obtained, [Zn₁₀Cl₁₂(ESiMe₃)₄(PⁱPr₃)₄] (E = P 3 , As 4 ). As a result of the reaction of CdBr₂ with P(SiMe₃)₃ the compound [CdBr₂{P(SiMe₃)₃}]₂ ( 5 ) can be isolated at –40 °C. In the presence of PⁿPr₃ CdBr₂ reacts with P(SiMe₃)₃ forming the binuclear complex [Cd₂Br₂{P(SiMe₃)₂}₂(PⁿPr₃)₂] · thf ( 6 ). The same reaction with PⁱPr₃ yields to the cluster [Cd₁₀Br₁₂(PSiMe₃)₄{P(SiMe₃)₃}₄] · 2 C₇H₈ ( 7 ). ZnI₂ and CdI₂ react with As(SiMe₃)₃ to yield the complexes [MI₂{As(SiMe₃)₃}]₂ (M = Zn 8 , Cd 9 ). In the case of CdI₂ additionally the cluster [Cd₁₀I₁₂(AsSiMe₃)₄ · {As(SiMe₃)₃}₄] · 4,5 C₇H₈ ( 10 ) is formed which is analogous to the compounds 3 , 4 and 7 . In the presence of [PⁿBu₄]I 8  reacts in THF to give the ionic compound [PⁿBu₄]₂[Zn₆I₆(AsSiMe₃)₄(thf)₂] · C₆H₆ ( 11 ).     

Subvalente Galliumtriflate – mögliche Ausgangsverbindungen für Clusterverbindungen des Galliums

Subvalent Gallium Triflates – Potentially Useful Starting Materials for Gallium Cluster Compounds By reaction of GaCp* with trifluormethanesulfonic acid in hexane a mixture of gallium trifluormethanesulfonates (triflates, OTf) is obtained. This mixture reacts readily with lithiumsilanides [Li(thf)₃Si(SiMe₃)₂R] (R = Me, SiMe₃) to afford the cluster compounds [Ga₆{Si(SiMe₃)Me}₆], [Ga₂{Si(SiMe₃)₃}₄] and [Ga₁₀{Si(SiMe₃)₃}₆]. By crystallization from various solvents the gallium triflates [Ga(OTf)₃(thf)₃], [HGa(OTf)(thf)₄]⁺ [Ga(OTf)₄(thf)₃]⁻, [Cp*GaGa(OTf)₂]₂ and [Ga(toluene)₂]⁺ [Ga₅(OTf)₆(Cp*)₂]⁻ were isolated and characterized by single crystal X ray structure analysis.     

Molecular Gallium Arsenide Phosphide Clusters Prepared from AsP3, P4, and [{GaC(SiMe3)3}4]

Treatment of AsP₃ with 0.75 equivalents of [{GaC(SiMe₃)₃}₄] resulted in selective insertion of three equivalents of {GaC(SiMe₃)₃} into the three As? P bonds to give [As{GaC(SiMe₃)₃}₃P₃] ( 1 ‐As) with an intact cyclo‐P₃ ring. This yellow compound has been characterized by NMR spectroscopy, combustion analysis, single‐crystal X‐ray diffraction, UV/Vis spectroscopy, Raman spectroscopy, and cyclic voltammetry (THF, 0.2 M [TBA][B(C₆F₅)₄]; TBA=tetrabutyl ammonium). Computational models of 1 ‐As and the isomeric [P{GaC(SiMe₃)₃}₃AsP₂] ( 1 ‐P) have been investigated as well, revealing several interesting electronic features of these cage molecules. Following from the cyclic voltammetry studies of 1 ‐As that highlight an irreversible two‐electron reduction at ?2.2 V versus Fc/Fc⁺, treatment with one equivalent of [Mg(C₁₄H₁₀)(thf)₃] resulted in two‐electron reduction to provide [As{GaC(SiMe₃)₃}₃P₃Mg(thf)₃] ( 2 ), in which the Mg²⁺ ion has inserted into one of the P? P bonds of the cyclo‐P₃ ring. It was also found that treatment of AsP₃ or P₄ with one equivalent of [{GaC(SiMe₃)₃}₄] resulted in formation of the quadruple insertion products [As{GaC(SiMe₃)₃}₄P₃] ( 3 ) and [P{GaC(SiMe₃)₃}₄P₃] ( 4 ), respectively.     

[{(CH3)3Si}3C–Li–C{Si(CH3)3}3][Li · 3(OC4H8)] und {(CH3)3Si}3C–Li · O=C(Si(CH3)3)2, zwei neue Addukte des Lithium‐trisylmethanids

[{(CH₃)₃Si}₃C–Li–C{Si(CH₃)₃}₃][Li · 3(OC₄H₈)] and {(CH₃)₃Si}₃C–Li · O=C(Si(CH₃)₃)₂, two New Adducts of Lithium Trisylmethanide Sublimation of (Tsi–Li) · 2 THF (Tsi = –C(Si(CH₃)₃)₃) at 180 °C and 10^–4 hPa gives (Tsi–Li) · 1.5 THF in very low yield. The X‐ray structure determination shows an almost linear [Tsi–Li–Tsi]^– anion connected by short agostic Li…C contacts with the threefold THF‐coordinated Li‐cation. Base‐free Tsi–Li, solved in toluene is decomposed by oxygen, forming the strawberry‐colored ketone O=C(SiMe₃)₂, which forms an 1 : 1 adduct with undecomposed Tsi–Li. The X‐ray structure elucidation of this compound is also discussed.     

Synthesis and characterisation of [AlMen{Si(SiMe3)3}3−n(thf)] (n = 1 or 2)

The crystalline compounds [AlMe_n{Si(SiMe₃)₃}_3−n(thf)] [n = 2 (1) or 1 (2)] were prepared from the lithium sisyl [Li{Si(SiMe₃)₃}(thf)₃] (A) and the appropriate methylaluminium chloride [AlCl_3−nMe_n] in thf. The X-ray structure of 1 is reported. Unlike A or a magnesium sisyl [Mg{Si(SiMe₃)₃}₂(thf)₂] (B), neither 1 nor 2 underwent an insertion reaction with an α-H-free nitrile.     

Synthesis and Structural Characterization of Several Ytterbium Bis(trimethylsilyl)amides Including Base‐free [Yb{N(SiMe3)2}2(μ‐Cl)]2 — A Coordinatively Unsaturated Complex with Additional Agostic Yb···(H3C—Si) Interactions

The reaction of YbCl₃ with two equivalents of NaN‐(SiMe₃)₂ has afforded a mixture of several ytterbium bis(trimethylsilyl) amides with the known complexes [Yb{N(SiMe₃)₂}2(μ‐Cl)(thf)]₂ ( 1 ) and [Yb{N(SiMe₃)₂}₃]( 4 ) as the main products and the cluster compound [Yb₃Cl₄O{N(SiMe₃)₂}₃(thf)₃]( 2 ) as a minor product. Treatment of 1 and 2 with hot n‐heptane gave the basefree complex [Yb{N(SiMe₃)₂}₂(μ‐Cl)]₂ ( 3 ) in small yield. The structures of compounds 1—4 and the related peroxo complex [Yb₂{N(SiMe₃)₂}₄(μ‐O₂)(thf)₂]( 5 ) have been investigated by single crystal X‐ray diffraction. In the solid‐state, 3 shows chlorobridged dimers with terminal amido ligands (av. Yb—Cl = 262.3 pm, av. Yb—N = 214.4 pm). Additional agostic interactions are observed from the ytterbium atoms to four methyl carbon atoms of the bis(trimethylsilyl)amido groups (Yb···C = 284—320 pm). DFT calculations have been performed on suitable model systems ([Yb₂(NH₂)₄(μ‐Cl)₂(OMe₂)₂]( 1m ), [Yb₂(NH₂)₄(μ‐Cl)₂]( 3m ), [Yb‐(NH₂)₃]( 4m ), [Yb₂(NH2₄(μ‐O₂)(OMe₂)₂]( 5m ), [Yb{N‐(SiMe₃)₂}₂Cl] ( 3m/2 ) and Ln(NH₂)₂NHSiMe₃ (Ln = Yb ( 6m ), Y ( 7m )) in order to rationalize the different experimentally observed Yb—N distances, to support the assignment of the O—O stretching vibration (775 cm ^‐1) in the Raman spectrum of complex 5 and to examine the nature of the agostic‐type interactions in σ‐donorfree 3 .     

Synthese und Strukturen neuer Ringverbindungen des Bismuts mit Tris(trimethylsilyl)silyl und ‐stannylresten – [(Me3Si)3Si]4Bi4 und [(Me3Si)3Sn]6Bi8

Synthesis and Structures of Novel Ring Compounds of Bismuth with Tris(trimethylsilyl)silyl and ‐stannyl Substituents – [(Me₃Si)₃Si]₄Bi₄ and [(Me₃Si)₃Sn]₆Bi₈ A bicyclo[3.3.0]octane‐like core consisting of eight bismuth atoms is found in the novel octabismuthane Bi₈[Sn(SiMe₃)₃]₆. It is prepared like Bi₄[Si(SiMe₃)₃]₄ by reduction of BiBr₃ with Li(thf)₃E(SiMe₃)₃ (E = Si, Sn) together with (Me₃Si)₆E₂. Both bismuth ring compounds have been characterized by single crystal X‐ray crystallography.     

First Copper(I) and Silver(I) Complexes Containing Phosphanylphosphido Ligands

Three new complexes with phosphanylphosphido ligands, [Cu₄{μ₂‐P(SiMe₃)‐PtBu}₄] ( 1 ), [Ag₄{μ₂‐P(SiMe₃)‐PtBu₂}₄] ( 2 ) and [Cu{η¹‐P(SiMe₃)‐PiPr₂}₂]^–[Li(Diglyme)₂]⁺ ( 3 ) were synthesized and structurally characterized by X‐ray diffraction, NMR spectroscopy, and elemental analysis. Complexes 1 and 2 were obtained in the reactions of lithium derivative of diphosphane tBu₂P‐P(SiMe₃)Li · 2.7THF with CuCl and [iBu₃PAgCl]₄, respectively. The X‐ray diffraction analysis revealed that the complexes 1 and 2 present macrocyclic, tetrameric form with Cu₄P₄ and Ag₄P₄ core. Complex 3 was prepared in the reaction of CuCl with a different derivative of lithiated diphosphane iPr₂P‐P(SiMe₃)Li · 2(Diglyme). Surprisingly, the X‐ray analysis of 3 revealed that in this reaction instead of the tetramer the monomeric form, ionic complex [Cu{η¹‐P(SiMe₃)‐PiPr₂}₂]^–[Li(Diglyme)₂]⁺ was formed.     

Highly Fluorinated Tris(indazolyl)borate Silylamido Complexes of the Heavier Alkaline Earth Metals: Synthesis,Characterization, and Efficient Catalytic Intramolecular Hydroamination

Heteroleptic silylamido complexes of the heavier alkaline earth elements calcium and strontium containing the highly fluorinated 3‐phenyl hydrotris(indazolyl)borate {F₁₂‐Tp^{4Bo, 3Ph}}^? ligand have been synthesized by using salt metathesis reactions. The homoleptic precursors [Ae{N(SiMe₃)₂}₂] (Ae=Ca, Sr) were treated with [Tl(F₁₂‐Tp^{4Bo, 3Ph})] in pentane to form the corresponding heteroleptic complexes [(F₁₂‐Tp^{4Bo, 3Ph})Ae{N(SiMe₃)₂}] (Ae=Ca ( 1 ); Sr ( 3 )). Compounds 1 and 3 are inert towards intermolecular redistribution. The molecular structures of 1 and 3 have been determined by using X‐ray diffraction. Compound 3 exhibits a Sr ??? MeSi agostic distortion. The synthesis of the homoleptic THF‐free compound [Ca{N(SiMe₂H)₂}₂] ( 4 ) by transamination reaction between [Ca{N(SiMe₃)₂}₂] and HN(SiMe₂H)₂ is also reported. This precursor constitutes a convenient starting material for the subsequent preparation of the THF‐free complex [(F₁₂‐Tp^{4Bo, 3Ph})Ca{N(SiMe₂H)₂}] ( 5 ). Compound 5 is stabilized in the solid state by a Ca???β‐Si?H agostic interaction. Complexes 1 and 3 have been used as precatalysts for the intramolecular hydroamination of 2,2‐dimethylpent‐4‐en‐1‐amine. Compound 1 is highly active, converting completely 200 equivalents of aminoalkene in 16 min with 0.50 mol % catalyst loading at 25 °C.     

Tris[bis(trimethysilyl)amido]zinkate von Lithium und Calcium

Tris[bis(trimethylsilyl)amido]zincates of Lithium and Calcium Calcium-bis[bis(trimethylsilyl)amide] and Bis[bis(trimethylsilyl)amido]zinc yield in 1,2-dimethoxyethane quantitatively Calcium-bis{tris[bis(trimethylsilyl)- amido]zincate} · 3DME. When THF is chosen as a solvent, the two reactants and the zincate form a temperature-independent equilibrium, whereas in benzene no reaction occurs. The tris[bis(trimethylsilyl)amido]zincate anion displays characteristic ¹³C{¹H) and ²⁹Si{¹H] chemical shifts of 7 and ?8 ppm, respectively; the nature of the solvent, the cation and the complexating ligands don't influence the IR nor NMR data of the zincate anion and thus verify that [Ca(DME)₃]²⁺ and {Zn[N(SiMe_{3 2}]₃}^? appear as solvent separated ions, which is also confirmed by their insolubility in hydrocarbons.     

Synthese und Strukturen von Yttrium‐tris[bis(trimethylsilyl)phosphanid] und 1, 1', 3, 3'‐Tetrakis(trimethylsilyl)yttrocen‐tri(tert‐butyl)silylphosphanid

The metalation of HP(SiMe₃)₂ with Y[CH(SiMe₃)₂]₃ gives the homoleptic {Y[P(SiMe₃)₂]₃}₂ (1) which crystallizes from toluene in the monoclinic space group P2₁/c. The yttrium atoms are in a distorted tetrahedral environment with Y‐P bond lengths of 267.7 and 284.8 pm to the terminal and bridging substituents, respectively. The metathesis reaction of [1, 3‐(Me₃Si)₂C₅H₃]₂YCl with KPSitBu₃ yields (tetrahydrofuran‐O)‐1, 1', 3, 3'‐tetrakis(trimethylsilyl)yttrocene‐tri(tert‐butyl)silylphosphanide ( 2 ). The molecular structure of 2 in solution was deduced by NMR spectroscopy and X‐ray crystallography. The coupling constants ¹J(Y, P) and ¹J(P, H) show values of 144.0 Hz and 201.0 Hz, respectively.     

Two‐Coordinate Iron(I) Complex [Fe{N(SiMe3)2}2]−: Synthesis,Properties, and Redox Activity

First‐row two‐coordinate complexes are attracting much interest. Herein, we report the high‐yield isolation of the linear two‐coordinate iron(I) complex salt [K(L)][Fe{N(SiMe₃)₂}₂] (L=18‐crown‐6 or crypt‐222) through the reduction of either [Fe{N(SiMe₃)₂}₂] or its three‐coordinate phosphine adduct [Fe{N(SiMe₃)₂}₂(PCy₃)]. Detailed characterization is gained through X‐ray diffraction, variable‐temperature NMR spectroscopy, and magnetic susceptibility studies. One‐ and two‐electron oxidation through reaction with I₂ is further found to afford the corresponding iodo iron(II) and diiodo iron(III) complexes.     

Highly Strained Heterometallacycles of Group 4 Metallocenes with Bis(diphenylphosphino)methanide Ligands

A study of the coordination chemistry of different bis(diphenylphosphino)methanide ligands [Ph₂PC(X)PPh₂] (X=H, SiMe₃) with Group 4 metallocenes is presented. The paramagnetic complexes [Cp₂Ti{κ²‐P,P‐Ph₂PC(X)PPh₂}] (X=H ( 3 a ), X=SiMe₃ ( 3 b )) have been prepared by the reactions of [(Cp₂TiCl)₂] with [Li{C(X)PPh₂}₂(thf)₃]. Complex 3 b could also be synthesized by reaction of the known titanocene alkyne complex [Cp₂Ti(η²‐Me₃SiC₂SiMe₃)] with Ph₂PC(H)(SiMe₃)PPh₂ ( 2 b ). The heterometallacyclic complex [Cp₂Zr(H){κ²‐P,P‐Ph₂PC(H)PPh₂}] ( 4 aH ) has been prepared by reaction of the Schwartz reagent with [Li{C(H)PPh₂}₂(thf)₃]. Reactions of [Cp₂HfCl₂] with [Li{C(X)PPh₂}₂(thf)₃] gave the highly strained corresponding metallacycles [Cp₂M(Cl){κ²‐P,P‐Ph₂PC(X)PPh₂}] ( 5 aCl and 5 bCl ) in very good yields. Complexes 3 a , 4 aH , and 5 aCl have been characterized by X‐ray crystallography. Complex 3 a has also been characterized by EPR spectroscopy. The structure and bonding of the complexes has been investigated by DFT analysis. Reactions of complexes 4 aH , 5 aCl , and 5 bCl did not give the corresponding more unsaturated heterometallacyclobuta‐2,3‐dienes.     

Functionalization of [Ge9] with Small Silanes:[Ge9(SiR3)3]– (R = iBu,iPr, Et) and the Structures of (CuNHCDipp)[Ge9{Si(iBu)3}3], (K‐18c6)Au[Ge9{Si(iBu)3}3]2, and (K‐18c6)2[Ge9{Si(iBu)3}2]

Novel silylation reactions at [Ge₉] Zintl clusters starting from the chlorosilanes SiR₃Cl (R = iBu, iPr, Et) and the Zintl phase K₄Ge₉ are reported. The formation of the tris‐silylated anions [Ge₉(SiR₃)₃]^– [R = iBu ( 1a ), iPr ( 1b ), Et ( 1c )] by heterogeneous reactions in acetonitrile was monitored by ESI‐MS measurements. For R = iBu ¹H, ¹³C and ²⁹Si NMR experiments confirmed the exclusive formation of 1a . Subsequent reactions of 1a with CuNHC^DippCl and Au(PPh₃)Cl result in formation of the neutral metal complex (CuNHC^Dipp)[Ge₉{Si(iBu)₃}₃]·0.5 tol ( 2 ·0.5 tol) and the metal bridged dimeric unit {Au[Ge₉{Si(iBu)₃}₃]₂}^– ( 3a ), isolated as a (K‐18c6)⁺ salt in (K‐18c6)Au[Ge₉{Si(iBu)₃}₃]₂·tol ( 3 ·tol), respectively. Finally, from a toluene/hexane solution of 1a in presence of 18‐crown‐6, crystals of the compound (K‐18c6)₂[Ge₉{Si(iBu)₃}₂]·tol ( 4 ·tol), containing the bis‐silylated cluster anion [Ge₉(Si(iBu)₃)₂]^2– ( 4a ), were obtained. The compounds 2 ·0.5 tol, 3 ·tol and 4 ·tol were characterized by single‐crystal structure determination.     

Two‐Coordinate Iron(I) Complex [Fe{N(SiMe3)2}2]−: Synthesis,Properties, and Redox Activity

First‐row two‐coordinate complexes are attracting much interest. Herein, we report the high‐yield isolation of the linear two‐coordinate iron(I) complex salt [K(L)][Fe{N(SiMe₃)₂}₂] (L=18‐crown‐6 or crypt‐222) through the reduction of either [Fe{N(SiMe₃)₂}₂] or its three‐coordinate phosphine adduct [Fe{N(SiMe₃)₂}₂(PCy₃)]. Detailed characterization is gained through X‐ray diffraction, variable‐temperature NMR spectroscopy, and magnetic susceptibility studies. One‐ and two‐electron oxidation through reaction with I₂ is further found to afford the corresponding iodo iron(II) and diiodo iron(III) complexes.     

Low‐Coordinate Barium Boryloxides: Synthesis and Dehydrocoupling Catalysis for the Production of Borasiloxanes

The first soluble barium boryloxides [Ba]– OB{CH(SiMe₃)₂} are presented. These mono‐ or dinuclear complexes feature low coordination numbers, as low as two for [Ba(OB{CH(SiMe₃)₂}₂)₂], which is further stabilized by intra‐ and intermolecular Ba???H₃C agostic interactions. Barium boryloxides and the parent [Ba{N(SiMe₃)₂}₂?(thf)₂] catalyze the dehydrocoupling of borinic acids with hydrosilanes, providing borasiloxanes under mild conditions.