Die Molekül- und Kristallstrukturen von (CO)4 W(μ-S-t-C4H9)2W(CO)4, η7-C7H7W(μ-SC6H4CH3)3W(CO)3 und η7-C7H7W(μ-S-n-C4H9)3W(CO)(μ-S-n-C4H9)2W(CO)4

Molecular and Crystal Structures of (CO)₄W(μ-S-t-C₄H₉)₂W(CO)₄, η⁷-C₇H₇W(μ-SC₆H₄CH₃)₃W(CO)₃ and η⁷-C₇H₇W(μ-S-n-C₄H₉)₃W(CO)(μ-S-n-C₄H₉)₂W(CO)₄ The molecular structures of the two binuclear complexes (CO)₄W(μ-S-t-C₄H₉)₂W(CO)₄ and η⁷-C₇H₇W(μ-SC₆H₄CH₃)₃W(CO)₃ and of the tungsten cluster η⁷-C₇H₇W(μ-S-n-C₄H₉)₃W(CO)-(μ-S-n-C₄H₉)₂W(CO)₄ respectively are described. In the nonlinear trinuclear cluster the central tungsten atom is connected to the two tungsten atoms by two and three μ-S-n-C₄H₉ bridges respectively and additionally by one W? W bond each. The coordination sphere of the W atoms is completed by a η⁷-C₇H₇ ring and four CO groups respectively; the central tungsten carries an additional CO group.     

Röntgenstrukturanalyse eines Carben-Additionsproduktes an Dicarbonyl-η5-methylcyclopentadienyl-Tetrahydrofuranmangan, μ-Cyclobuta[1, 2-a:3, 4-a′] dicyclopenten-bis[dicarbonyl-η5-methylcyclopentadienylmangan], [(η5-C5H4CH3)Mn (CO)2]2(μ2-C10H8)

X-Ray Structure Analysis of a Carbene Addition Product to Dicarbonyl-η⁵-methylcyclopentadienyltetrahydrofuranmanganese, μ-Cyclobuta[1, 2-a:3, 4-a′] dicyclopentene-bis-(dicarbonyl-η⁵-methylcyclopentadienylmanganese),[( η⁵-C₅H₄CH3)Mn(CO) ₂]₂(μ₂-C₁₀H₈) The crystal and molecular structure of the title compound has been determined by means of X-ray structure analysis. The species is the first example of an oligocyclic dicarbene stabilized by complex formation.     

Reaktionen der Cycloheptatrienylkomplexe [η7-C7H7W(CO)3]BF4 und η7-C7H7Mo(CO)2 Br mit Neutralliganden und die elektrochemische Reduktion des Wolframkomplexes

Reactions of the Cycloheptatrienyl Complexes [η⁷-C₇H₇W(CO)₃]BF₄ and η⁷-C₇H₇Mo(CO)₂Br with Neutral Ligands and the Electrochemical Reduction of the Wolfram Complex Compounds of the type [η⁷-C₇H₇M(CO)₂L][BF₄] (L = P(C₆H₅)₃, As(C₆H₅)₃, Sb(C₆H₅)₃ for M = W and L = N₂H₄ for M = Mo) were synthesized and characterisized. The iodide η⁷-C₇H₇W(CO)₂I reacts with the diphosphine ((C₆H₅)₂PCH₂)₂ to give the trihapto complex η³-C₇H₇ W(CO)₂I((C₆H₅)₂PCH₂)₂. In the case of η⁷-C₇H₇Mo(CO)₂ Br reaction with hydrazine leads to the substitution product [η⁷-C₇H₇ Mo(CO)₂N₂H₄]^⊕, which can be stabilized by large anions. The binuclear complex [C₇H₇W(CO)₃]₂ has been synthesized electrochemically.     

Heterometallische Clusterkomplexe der Typen Re2(μ-PR2)(CO)8(HgY) und ReMo(μ-PR2)(η5-C5H5)(CO)6(HgY) (R = Ph,Cy; Y = Cl,W(η5-C5H5)(CO)3)

Heterometallic Cluster Complexes of the Types Re₂(μ-PR₂)(CO)₈(HgY) and ReMo(μ-PR₂)(η⁵-C₅H₅)(CO)₆(HgY) (R = Ph, Cy; Y = Cl, W(η⁵-C₅H₅)(CO)₃) Dinuclear complexes Re₂(μ-H)(μ-PR₂)(CO)₈ and ReMo(μ-H)(μ-PR₂)(η⁵-C₅H₅)(CO)₆ (R = phenyl, cyclohexyl) were deprotonated and reacted as anions with HgCl₂ to compounds of the both types Re₂(μ-PR₂)(CO)₈HgCl) and ReMo(μ-PR₂)(η⁵-C₅H₅)(CO)₆(HgCl). The heterometallic three-membered cluster complexes correspond to an isolobal exchange of a proton against a cationic HgCl⁺ group. For one of the products ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgCl) has been shown its conversion with NaW(η⁵-C₅H₅)(CO)₃ to ReMo(μ-PCy₂)(η⁵-C₅H₅)(HgW(η⁵-C₅H₅)(CO)₃) under substitution of the chloro ligand, par example. The newly prepared compounds were characterized by means of IR, UV/VIS and ³¹P NMR data. A complete determination of the molecular structure by single crystal analyses was done in the case of Re₂(μ-PCy₂)(CO)₈(HgCl) and of ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgCl) which both are dimer because of the presence of an asymmetric dichloro bridge, and of ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgW(η⁵-C₅H₅)(CO)₃). The structural study illustrates through comparison the influence of various metal types on an interaction between centric and edge-bridged frontier orbitals in three-membered metal rings.     

Synthese und Eigenschaften der heteronuklearen Metallatomcluster Re4(CO)12[μ3-GaRe(CO)5]4 und Re2(CO)3[μ-GaRe(CO)5]2

Synthesis and Properties of Heteronuclear Metal Atom Clusters Re₄(CO)₁₂[μ₃-GaRe(CO)₅]₄ and Re₂(CO)₈[μ-GaRe(CO)₅]₂ The title compounds were prepared by the reaction of gallium halides and dirhenium decacarbonyl. Crystals of the four-membered cluster Re₂(CO)₈[μ-GaRe(CO)₅]₂ gave at 300⁰C with aggregation of four Re atoms to an inner Re₄ tetrahedron the product Re₄(CO)₁₂(CO)[μ₃-GaRe(CO)₅]₄and with Ga₂I₃ shown by mass spectroscopic measurements the molecule ion Re₄(CO)₁₆+. In tetra-hydrofuran solution the cluster Re₄(CO)₁₂[μ₃-GaRe(CO)₅]₄ and the hydride Li[C₂H₅)₃BH] have formed the formyl complex Li₄{Re₄(CO)₁₂[μ₃ -GaRe(CO)₄(CHO)] ₄}, which was estimated by ¹H n. m. r. and i. r. spectroscopic data. Both synthesized gallium rhenium carbonyl clusters were characterized by i.r. spectroscopic measurements. The comparison of these results with those of the structurally known indium rhenium carbonyl clusters led to proposals of the molecule structure of the analogous gallium rhenium compounds.     

New 1,1′-Ring-substituted Vanadocene Dichlorides. Crystal structures of [V(η5-C5H4SiMe3)2Cl2] and [V(η5-C5H5)2Cl2]

The 1,1′-ring-substituted vanadocene dichlorides [V(η⁵-C₅H₄R)₂Cl₂] (R = CMe₃, SiMe₃, SiEt₃) have been prepared from VCl₄ and the appropriate lithiated cyclopentadiene, C₅H₄RLi, in 1 : 2 ratios. All complexes were characterized by elemental microanalysis and IR spectroscopy. The crystal structures of [V(η⁵-C₅H₄SiMe₃)₂Cl₂] 3 and the parent compound [V(η⁵-C₅H₅)₂Cl₂] 1 have been determined by X-ray diffraction and are in accordance with expectations. Compound 1 crystallizes with two crystallographically independent molecules in its monoclinic unit cell. These two molecules are quite similar in their essential structural features. Compound 3 crystallizes in the triclinic space group P1 . The trimethylsilylcyclopentadienyl rings are bound in a staggered relative orientation.