Cr8S11Cl2 – das erste Chromthiochlorid

Cr₈S₁₁Cl₂ – the First Chromium Thiochloride Cr₈S₁₁Cl₂ was obtained by reaction of CrCl₃ with H₂S at 650 K. X-ray, magnetic and thermal properties have been investigated.     

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.     

Bildung und Struktur des iso-Tetraphosphans P[P(SiMe3)Me]3

Formation and Structure of iso-Tetraphosphane P[P(SiMe₃)Me]₃ The reaction of MeP(SiMe₃)₂ with PCl₃ (molar ratio 3:1, ?78°C, n-pentane) yields by cleaving of the P? Si bond P[P(SiMe₃)Me]₃ 1 with Cl₂P? P(SiMe₃)Me and ClP[P(SiMe₃)Me]₂ as intermediates. The reaction rate decreases by the increase of phosphorylation. The last reaction step (formation of 1 ) occurs while warming up to room temperature. 1 forms colorless hexagonal crystals, melting point 65 ± 1°C. Tris(trimethylsilyl-methyl-phosphino)phosphane 1 crystallizes monoclinically in the space group Cc (No. 8) with Z = 8 formula units per unit cell. The molecules possess approximated C₃ symmetry and have (RRR) and (SSS) configurations, respectively. The bond distances d?(P? P) = 220.1 pm, d?(P? C) = 186.5 pm, and d?(P? Si) = 225.2 pm are normal and within the expected range of known distances. According to repulsive interactions between the non bonded electron pairs of the terminal P atoms and the protons of the methyl groups the angles at the central and terminal P atoms are enlarged to ? P P P = 105.1° and ? P P C = 106.9°, respectively.     

Synthese eines funktionalen Aluminiumalkinids,Me3C‐C≡C‐AlBr2, und dessen Reaktionen mit der sperrigen Lithiumverbindung LiCH(SiMe3)2

Synthesis of a Functional Aluminium Alkynide, Me₃C‐C≡C‐AlBr₂, and its Reactions with the Bulky Lithium Compound LiCH(SiMe₃)₂ Treatment of aluminium tribromide with the lithium alkynide (Li)C≡C‐CMe₃ afforded the aluminium alkynide Me₃C‐C≡C‐AlBr₂ ( 1 ) in an almost quantitative yield. 1 crystallizes with trimeric formula units possessing Al₃C₃ heterocycles and the anionic carbon atoms of the alkynido groups in the bridging positions. A dynamic equilibrium was determined in solution which probably comprises trimeric and dimeric formula units. Reaction of 1 with one equivalent of LiCH(SiMe₃)₂ yielded the compound [Me₃C‐C≡C‐Al(Br)‐CH(SiMe₃)₂]₂ ( 2 ), which is a dimer via Al‐C‐Al bridges. Two equivalents of the lithium compound gave a mixture of four main‐products, which could be identified as 2 , Li[Me₃C‐C≡C‐Al{CH(SiMe₃)₂}₃] ( 3 ), Me₃C‐C≡C‐Al[CH(SiMe₃)₂]₂ ( 4 ), and Al[CH(SiMe₃)₂]₃. The lithium atom of 3 is coordinated by the C≡C triple bond and an inner carbon atom of one bis(trimethylsilyl)methyl group. Further interactions were observed to C‐H bonds of methyl groups.     

[Li(12-Krone-4){(Me3Si)2N}2TiCH2SiMe2NSiMe3] – ein Ionenpaar mit gestreckter Li–C–Ti-Achse

[Li(12-Crown-4){(Me₃Si)₂N}₂TiCH₂SiMe₂NSiMe₃] – an Ion-Pair with a Linear Li–C–Ti-Axis The title compound ( 1 ) has been prepared from Ti[N(SiMe₃)₂]₃ and n-butyllithium in OEt₂/n-hexane in the presence of 12-crown-4. Smaragd-green single crystals of 1 · C₇H₈ which were suitable for X-ray crystallography were formed from toluene solutions at –18 °C. According to the crystal structure determination 1 forms ion pairs between the lithium atom and the CH₂-carbon atom which is member of a planar Ti–C–Si–N heterocycle. The coordination geometry of the Li–C–Ti axis is linear (bond angle 172.8° in average of the two symmetry independent species) with coordination number five at the CH₂-carbon atom.     

Cobalt(II)-organische Phosphaniminato-Komplexe mit Heterocuban-Struktur. Kristallstrukturen von [CoBr(NPR3)]4 mit R = Me,Et, [Co(C≡C–CMe3)(NPMe3)]4 und [Co(C≡C–SiMe3)(NPEt3)]4

Organo-Cobalt(II) Phosphorane Iminato Complexes with Heterocubane Structures. Crystal Structures of [CoBr(NPR₃)]₄ with R = Me, Et, [Co(C≡C–CMe₃)(NPMe₃)]₄, and [Co(C≡C–SiMe₃)(NPEt₃)]₄ The phosphorane iminato complexes [CoBr(NPR₃)]₄, which are accessible by reaction of CoBr₂ with the silylated phosphorane imines Me₃SiNPR₃ (R = Me, Et) in the melt at 180 °C and in the presence of KF, can be transformed into the alkynyl complexes [Co(C≡C–CMe₃) · (NPMe₃)]₄ and [Co(C≡C–SiMe₃)(NPEt₃)]₄ on obtaining the heterocubane structures, when caused to react with the lithium organic reagents LiC≡C–CMe₃ and LiC≡C–SiMe₃ in THF at 0 °C. According to the crystal structure analyses all four of the compounds form heterocubane structures with only slightly distorted Co₄N₄ cubic structures.     

Die Reaktionen von tBu2P–P=P(Me)tBu2 und (Me3Si)tBuP–P=P(Me)tBu2 mit PR3

The Reactions of ^tBu₂P–P=P(Me)^tBu₂ and (Me₃Si)^tBuP–P=P(Me)^tBu₂ with PR₃ ^tBu₂P–P=P(Me)^tBu₂ ( 1 ) reacts at 20 °C with PMe₃, PEt₃, P(c‐Hex)₃, P(p‐Tol)₃, PPh₂Me, PPh₂Et, PPhEt₂, PPh₂ⁱPr, PPh₃ and P(NEt₂)₃ yielding ^tBu₂P–P=PR₃ and ^tBu₂PMe; however, P^tBu₃, P^tBu₂(SiMe₃) and ^tBu₂PCl don't. ^tBu₂PH and 1 form ^tBu₂P–PH–P^tBu₂ which yields ^tBu₂P–P=PEt₃ when treated with PEt₃. Ph₂PH, ^tBuPH₂, PH₃, Ph₂PCl and EtOH don't substitute the ^tBu₂PMe group in 1 , instead, the molecule is decomposed. With PEt₃, (Me₃Si)^tBuP–P=P(Me)^tBu₂ forms (Me₃Si)^tBuP–P=PEt₃. The compounds ^tBu₂P–P=PR₃ decompose at 20 °C to different degrees giving P‐rich consecutive products of the phosphinophosphinidene.     

Darstellung und Strukturen neuartiger Triphenylsilylund Triphenylgermyl‐substituierter Gallane und Oligogallane – [Ga3(GePh3)6]–, das erste lineare Trigallan

Chemistry of Gallium. 20. Synthesis and Structures of Novel Triphenylsilyl and Triphenylgermyl Substituted Gallanes and Oligogallanes – [Ga₃(GePh₃)₆]^–, the First Linear Trigallane From the raction of sonochemically prepared “GaI” with LiEPh₃ (E = Si, Ge) the compounds [Li(THF)₂][GaI(EPh₃)₃] (E = Si: 22 , E = Ge: 24 ), [Li(THF)₄][GaI(SiPh₃)₃] ( 23 ), [Li(THF)₄][Ga₂(SiPh₃)₅] ( 21 ) and [Li(THF)₄][Ga₃(GePh₃)₆] ( 25 ) as well as polymeric Li(THF)I ( 20 ) were obtained and structurally characterized. 21 is a monoanionic digallane, exhibiting a trigonal planar and a tetrahedrally coordinated gallium centre. 25 has a linear Ga₃ core, where the terminal gallium atoms bear three GePh₃‐groups, each. The central Ga atom is only 2‐coordinated. Thus, 25 may be a valuable hint to the formation of larger gallium clusters with “naked” gallium atoms. Derivatives of 21 and 25 have been studied by DFT methods.