Bildung und Kristallstruktur eines dimeren sauerstoffverbrückten Titanaminobisphenoxides

Formation and Crystal Structure of an Oxygen Bridged Titanium Amino Bisphenoxide Di‐(μ‐oxo)‐titan‐bis[aminobisphenoxide] ( 3 ) was obtained by reaction of (i‐Prop)₂TiL* ( 2 ) {L* = O‐4, 6‐(t‐Bu)₂C₆H₂‐2‐CH₂‐[1, 4‐N₂C₅H₁₀]‐2'‐CH₂‐4', 6'‐(t‐Bu)₂C₆H₂O] with water in a molar ratio 1:1 in diethylether. Both i‐Propyl moieties are substituted yielding the dimeric oxygen bridged amino bisphenoxide complex. The six coordinate Ti atoms are a result of Ti—N and Ti—O interactions of the corresponding atoms of the amino bisphenoxide ligand and the bridging O atoms. The central planar Ti₂O₂ ring may be considered as the general structural feature of the title compound: Space group P1¯, Z = 1, lattice dimensions at —60°C: a = 11.6899(4), b = 11.7873(4), c = 12.6462(4) Å, α = 98.070(1), β = 99.660(1), γ = 95.343(1)°, R₁ = 0.0469, wR₂ = 0.1049, GooF = 0.939.     

Spektroskopische und röntgenographische Untersuchungen an methylenverbrückten Organoantimonverbindungen

Spectroscopic and X-Ray Structure Investigations on Methylene Bridged Organoantimony Compounds The vibrational spectra of (Me₂Sb)₂CH₂ and of the halogen derivatives (Me₂Cl₂Sb)₂CH₂ and (Me₂Br₂Sb)₂CH₂ (Me = CH₃) have been measured and discussed. The i.r. and Raman data for liquid bis(dimethylstibino)methane are consistent with a mixture of two rotamers of C_s and C_2v symmetry, respectively. For the halogen compounds only one form is spectroscopically proved. The X-ray structure determination of (Me₂Cl₂Sb)₂CH₂ · CH₂Cl₂ shows the monoclinic space group P2₁/n with a = 968.2; b = 1746.8; c = 982.2 pm and β = 91.95°. The structure was refined to an R-value of 0.038.     

Synthese und Molekülstrukturen von amido‐ und imidoverbrückten Clustern elektronenreicher Übergangsmetalle

Synthesis and Structures of Amido‐ and Imidobridged Clusters of Electron‐rich Transition Metals We report in this article the results, which could be obtained within the DFG‐Project “Nitridobrücken zwischen Übergangsmetallen und Hauptgruppenelementen”. Reactions of electron‐rich transition metal compounds with either stannylated or lithiated amine derivatives lead in the presence of phosphines in different organic solvents to the formation of a large amount of nitrogenbridged transition metal clusters. The structures of 1 — 27 have been characterized by single crystal X‐ray‐structure analysis.     

Eisen- und Mangankomplexe mit sauerstoff-, schwefel- und methylen-verbrückten Distibanen und mit Chlorodiphenylstiban als Liganden

Complexes of Iron and Manganese with Oxygen-, Sulfur-, and Methylene-bridged Distibines and with Chlorodiphenylstibine as Ligands The photochemical reaction of CO₃Fe[P(OPh)₃]₂ and of MeCpMn(CO)₃ with the stibines Ph₂SbCl and (Ph₂Sb)₂X (X = O, S and CH₂) yields mononuclear complexes (CO)₂[P(OPh)₃]₂FeL and °Cp(CO)₂MnL (L = Ph₂SbCl, (Ph₂Sb)₂X) and the stibine bridged binuclear complexes °CO)₂[P(OPh)₃]₂Fe{(Ph₂Sb)₂X}Fe(CO)₂[P(OPh)₃]₂ and °Cp(CO)₂Mn{(Ph₂Sb)₂X}Mn(CO)₂MeCp.     

Synthese und eigenschaften von ortho-verbrückten diarylcyclopropenonen

A series of ortho-bridged diaryl cyclopropenones is prepared by straightforward synthetic pathways. The spectroscopic and chemical properties of the new cyclopropenones are reported.     

ZrIV‐ und TaV‐Komplexe mit methanoverbrückten Bis(aryloxy)‐Liganden

Zr^IV and Ta^V Complexes with Methano‐Bridged Bis(aryloxy) Ligands The bis(aryloxy) ligand precursor compounds bis(2‐trimethylsiloxy‐5‐tbutylphenyl)methane (L–SiMe₃) and its bromoderivative (2‐trimethylsiloxy‐3‐bromo‐5‐tbutylphenyl)(2′‐trimethylsiloxy‐5′‐tbutylphenyl)methane (L^Br–SiMe₃) are prepared in analogy to the corresponding calixarenes in excellent yields. X‐ray structure analysis for L^Br–SiMe₃: space group P2₁/c, a = 12.462(7), b = 10.466(6), c = 23.315(14) Å, β = 105.02(4)°, V = 2937(3) ų, Z = 4. L–SiMe₃ and L^Br–SiMe₃ react with Zr^IV and Ta^V chlorides in very good yields forming di‐ and trinuclear complexes. From the reaction of CpZrCl₃ with L^Br–SiMe₃ in the ratio of 3 : 2 a Zr₃ complex ( 7 ) is obtained, with one L^Br ligand only, which Zr atoms are bridged by a μ₃‐oxygen. The X‐ray structure analysis of 7 (space group R 3, a = 33.23(6), c = 24.47(8) Å, V = 23405(128) ų, Z = 18) additionally reveals that one phenolato oxygen atom of the L^Br ligand is terminally bound to a distorted tetragonal‐pyramidal coordinated Zr atom, while the second phenolato oxygen atom of the L^Br ligand forms a bridge to another Zr atom with a distorted octahedral coordination. The third Zr atom is also found in a distorted octahedral coordination mode. The reactions of L–SiMe₃ and L^Br–SiMe₃ with CpTaCl₄ and TaCl₅ yield dinuclear Ta complexes with a bridging bis(aryloxy) ligand. NMR spectroscopic data point out that the coordination of the bis(aryloxy) ligands in the Ta complexes very much resembles that in the Zr₃‐complex with one terminal and one bridging phenolato oxygen atom. The Zr₃ and the Ta complexes L^BrTa₂Cp₂Cl₆ and LTa₂Cl₈ were tested with respect to their catalytic properties in olefin polymerisation reactions in the presence of MAO.     

Tetra- und Pentacarbonyl-Derivate der Metalle Chrom,Molybdän und Wolfram mit sauerstoff- und schwefelverbrückten Distibanen sowie mit Chlorodiphenylstiban als Komplexliganden

Tetra- and Pentacarbonyl Compounds of Chromium, Molybdenum and Tungsten with Oxygen- and Sulfurbridged Distibines and with Chlorodiphenylstibine as Complex Ligands The penta- and tetracarbonyl complexes of chromium, molybdenum and tungsten with the stibines Ph₂SbCl and (Ph₂Sb)₂X (X = O and S) are obtained by photochemical reaction of the hexacarbonyls in thf and by thermic ligand substitution of (η⁴-C₇H₈)M(CO)₄ (M = Cr, Mo) with stibines. In the case of (Ph₂Sb)₂X monodentate or bidentate coordination is possible.     

Darstellung und Reaktionen von methylenverbrückten Phosphor(III)-Phosphor(V)-Verbindungen

Preparation and Reactions of Methylene-bridged Phosphorus(III)-Phosphorus(V) Compounds The synthesis of methylene-bridged diphosphorus compounds of the type Y₂PCH₂P(S)X₂ (with Y = F, Cl, OPrⁱ, NMe₂, Ph) is reported. Reactions of these compounds with bicycloheptadiene-metaltetracarbonyls to form complexes of the type (L? L′)M(CO)₄ and (L? L′)₂M(CO)₄, respectively, as well as some oxidation reactions and the conversion of the phosphine F₂PCH₂P(S)F₂ to the cyclotetraphosphine [PCH₂P(S)F₂]₄ are described.