Synthese verbrückter binuklearer Titanocenverbindungen – Kristallstruktur von Cl2Ti[(C5H4)(C5H4)(Me)Si–Si(Me)(C5H4)(C5H4)]TiCl2 · PhMe

Synthesis of Bridged Binuclear Titanocene Compounds – Crystal Structure of Cl₂Ti[(C₅H₄)(C₅H₄)(Me)Si–Si(Me)(C₅H₄)(C₅H₄)]TiCl₂ · PhMe Starting from Cp₂(Me)Si–Si(Me)Cp₂ 1 the complexes X₂Ti[(C₅H₄)(C₅H₄)(Me)Si–Si(Me)(C₅H₄)(C₅H₄)]TiX₂ (X = Cl ( 2 a ); X = Me ( 3 )) were synthesized. The compounds were characterized by means of their ¹H‐ and ¹³C‐n.m.r. and MS‐spectra. The crystal structure of 2 a · PhMe was determined.     

[{[(η7-C2B10H12)(η6-C2B10H12)U][K2(thf)5]}2]: A Metallacarborane Containing the Novel η7-C2B10H124− Ligand

The tetranion ligand η⁷-C₂B₁₀H₁₂⁴⁻ has been observed for the first time in 1 , which was obtained from the reaction of o-C₂B₁₀H₁₂ with excess K metal followed by treatment with UCl₄. As shown in the picture (without K cations and coordinated THF molecules), 1 is a centrosymmetric dimer with a bent sandwich structure.     

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.     

[(η5‐C5R5)TiCl2(η5‐C5H4SiMe2)]2O·nCH2Cl2

The first title metallocene, 1,3‐bis(dichlorotitanocene)‐1,1,3,3‐tetramethyldisiloxane dichloromethane solvate, [(η⁵‐C₅H₅)­TiCl₂­(η⁵‐C₅H₄­Si­Me₂)]₂O·­CH₂Cl₂, (I), crystallizes in space group P2₁/c. Compound (I) represents the first crystal structure of a bimetallic siloxy‐bridged titanocene. The geometric parameters of (I) are similar to those of the parent titanocene; however, the disiloxane substituents adopt an unexpected eclipsed conformation. The second title metallocene, 1,3‐bis­[(penta­methyl­cyclo­penta­dienyl)­(cyclo­penta­dien­yl)­titanium dichloride]‐1,1,3,3‐tetra­methyl­disiloxane, [(η⁵‐C₅‐Me₅)­TiCl₂­(η⁵‐C₅H₄­Si­Me₂)]₂O, (II), represents the second crystal structure of a bimetallic siloxy‐bridged titanocene and crystallizes in the space group P2₁/n. Compound (I) possesses non‐crystallographic twofold molecular symmetry and both metal centers adopt pseudo‐tetrahedral geometries. The geometric parameters of (II) are similar to those of the mixed titanocene Cp*CpTiCl₂ (Cp* = C₅Me₅) and the disiloxane substituents adopt a staggered conformation.     

Beiträge zur Chemie des Phosphors. 227. HP4º als Komplexligand: Bildung und Eigenschaften von [(η5-C5H5)2ZrCl(P4H)], [(η5-C5Me5)2ZrCl(P4H)] und [(η5-C5H5)3Zr(P4H)]

Contributions to the Chemistry of Phosphorus. 227. HP₄º as a Complex Ligand: Formation and Properties of [(η⁵-C₅H₅)₂ZrCl(P₄H)], [(η⁵-C₅Me₅)₂ZrCl(P₄H)], and [(η⁵-C₅H₅)₃Zr(P₄H)] The novel complexes [(η⁵-C₅H₅)₂ZrCl(P₄H)] ( 1 ), [(η⁵-C₅Me₅)₂ZrCl(P₄H)] ( 2 ), and [(η⁵-C₅H₅)₃Zr(P₄H)] ( 3 ) have been obtained by reaction of a solution of (Na/K)HP₄ with the zirconocen derivatives [(η⁵-C₅H₅)₂ZrCl₂], [(η⁵-C₅Me₅)₂ZrCl₂], and [(η⁵-C₅H₅)₃(η¹-C₅ H₅)Zr] under suitable conditions. The structure of the compounds 1 – 3 , which are only stable in solution, has been elucidated by means of ³¹P-NMR spectroscopy. It is highly probable that the exo,endo isomer exists in each case. In addition, further isomers of lower relative abundancies have been observed, in which the ligands presumably exhibit a different spatial orientation relatively to each other.     

Complexation of the 2, 4, 6‐Triallyloxy‐1, 3, 5‐triazine with Copper(I,II) Chlorides. Syntheses and Crystal Structures of [CuCl2·2C3N3(OC3H5)3], [Cu7Cl8·2C3N3(OC3H5)3], and [Cu8Cl8·2C3N3(OC3H5)3]·2C2H5OH

Interaction of copper(II) chloride with 2, 4, 6‐triallyloxy‐1, 3, 5‐triazine leads to formation of copper(II) complex [CuCl₂·2C₃N₃(OC₃H₅)₃] ( I ). Electrochemical reduction of I produces the mixed‐valence Cu^{I, II} π, σ‐complex of [Cu₇Cl₈·2C₃N₃(OC₃H₅)₃] ( II ). Final reduction produces [Cu₈Cl₈·2C₃N₃(OC₃H₅)₃]·2C₂H₅OH copper(I) π‐complex ( III ). Low‐temperature X‐ray structure investigation of all three compounds has been performed: I : space group P1¯, a = 8.9565(6), b = 9.0114(6), c = 9.7291(7) Å, α = 64.873(7), β = 80.661(6), γ = 89.131(6)°, V = 700.2(2) ų, Z = 1, R = 0.0302 for 2893 reflections. II : space group P1¯, a = 11.698(2), b = 11.162(1), c = 8.106(1) Å, α = 93.635(9), β = 84.24(1), γ = 89.395(8)°, V = 962.0(5) ų, Z = 1, R = 0.0465 for 6111 reflections. III : space group P1¯, a = 8.7853(9), b = 10.3602(9), c = 12.851(1) Å, α = 99.351(8), β = 105.516(9), γ = 89.395(8), V = 1111.4(4) ų, Z = 1, R = 0.0454 for 4470 reflections. Structure of I contains isolated [CuCl₂·2C₃N₃(OC₃H₅)₃] units. The isolated fragment of I fulfils in the structure of II bridging function connecting two hexagonal prismatic‐like cores Cu₆Cl₆, whereas isolated Cu₆Cl₆(CuCl)₂ prismatic derivative appears in III . Coordination behaviour of the 2, 4, 6‐triallyloxy‐1, 3, 5‐triazine moiety is different in all the compounds. In I ligand moiety binds to the only copper(II) atom through the nitrogen atom of the triazine ring. In II ligand is coordinated to the Cu^II‐atom through the N atom and to two Cu^I ones through the two allylic groups. In III all allylic groups and nitrogen atom are coordinated by four metal centers. The presence of three allyl arms promotes an acting in II and III structures the bridging function of the ligand moiety. On the other hand, space separation of allyl groups enables a formation of large complicated inorganic clusters.