Study of (π-C5H5)2Ti(C2H5)Cl and its higher homologs in soluble Ziegler catalysts

Soluble ethylene polymerization catalysts derived from (π-C₅H₅)₂Ti(R)Cl and R′AlCl₂ where R is ethyl or higher alkyl and R′ may be methyl or ethyl, were studied both by polymerization kinetics at 0°C and by diagnostic experiments. An early acceleration in rate occurred at this temperature in toluene solvent which was due to a solvent dependent increase in catalyst activity, not to a gradual formation of catalyst. No such solvent effect was found in nonaromatic solvents. The subsequent decay in rate, at least at low temperatures, did not depend upon valence reduction. The effect of Al/Ti ratio was studied, and certain discrepancies in the literature were shown to be due to the method of making kinetic measurements. Oxygen, which has previously been reported to affect the polymerization rate with these catalysts, was also found to eliminate the acceleration period in toluene when present in the amount of 1% of the catalyst. These catalysts gave polymers at low temperature for which the active site had long life and which did not undergo chain transfer. Therefore, they approximate many of the characteristics of living polymers.     

Die Strukturen der 1,3,5-Trisilacyclohexan-Eisendicarbonyl-cyclopentadienylkomplexe C3H6Si3Cl5Fe(CO)2πcp und C3H6Si3Cl4(Fe(CO)2πcp)2

Structures of the l,3,5-Trisilacyclohexane-Iron Dicarbonyl-cyclopentadienyl Complexes and C₃H₆Si₃Cl₅Fe(CO)₂πcp and C₃H₆Si₃Cl₄(Fe(CO₂)πcp)₂ Trisilapentachlorocyclo-hexyl-dicarbonylcyclopentadienyliron C₃H₆Si₃Cl₅Fe(CO)₂πcp 1 and Trisilatetrachlorocyclohexyl-bis(dicarboncyclopentadienyliron)C₃H₆Si₃Cl₄(Fe(CO)₂πcp)₂ 2 are 1,3,5-Trisilacyclohexane complexes substituted by dicarbonylcyclopentadienyliron at one and two silicon atoms of the six-membered ring, respectively. The crystal and molecular structures were determined from single crystals ( 1 ; space group P2₁/a (No. 14); a = 1100.5 pm; b = 2033.9 pm; c = 843.3pm; β = 98.58°; Z = 4; MoKα-radiation; 3142h k l; R = 0.036. 2 ; space group P1 ; (No. 2); a = 1231.1 pm; b = 1267.3 pm; c = 1045.9 pm; α = 113.23°; β = 83.93°; γ = 115.00°; Z = 2; Mokα-radiation; 4196 h k 1; R = 0.065). In both complexes the six-membered rings of the carbosilane ligands are in skew-boat conformation. The bond lengths Fe? Si are 226.4 pm and 228.1 pm, respectively. The distances Si? C and Si? Cl are 186 pm and 206 pm in 1 and 187 pm and 209 pm in 2 . Their different lengths depend on the position in the ligand system and can be explained with the concept of bond orders.     

Strukturchemie titan-organischer Verbindungen: Die Struktur von [(π-C5H5)2 Ti(NO3)]2O

Structural Chemistry of Organotitanium Compounds: Structure of [(π-C₅H₅)₂Ti(NO₃)]₂O Careful hydrolysis of (π-C₅H₅)₂Ti(NO₃)₂ in tetrahydrofuran yields crystals of [(π-C₅H₅)₂Ti(NO₃)]₂O ( A ). Crystal data of A : monoclinic, space group P2₁/c; lattice constants: a = 12.656(4), b = 10.181(5), c = 16.197(3) Å, ß = 93.57(3)º, Z = 4. As an X-ray analysis shows, the NO₃ groups act as monodentate ligands with Ti? O distances of 2.085 and 2.059 Å. The ligands are arranged in a nearly tetrahedral way around the Ti atoms. The bond angle at the bridging O atom is 171.8º.     

Schwingungsspektroskopische Untersuchungen an den Organohydrogensilanen (XCH2)(CH3)2SiH (X = Cl,Br, J), X(YO)2SiH (X = CH3, C2H5/Y = CH3, C2H5 … tert.-C4H9), (C6H5)2SiH2 und C6H5SiH3

Infrared and Raman Spectroscopic Investigations on the Organosubstituted Silicon Hydrides (XCH₂)(CH₃)₂SiH (X = Cl, Br, J), X(YO)₂SiH (X = CH₂, C₂H₅/Y = CH₃, C₂H₅ … tert.-C₄H₉), (C₆H₅)₂SiH₂ and C₆H₅SiH₃ Typical band splittings, specially for the SiH stretching vibration, are shown in the infrared and Raman spectra of the silicon hydrides (XCH₂)(CH₃)₂SiH (X = Cl, Br, J), and X(YO)₂SiH (X = CH₃, C₂H₅/Y = CH₃, C₂H₅ … tert.-C₄H₉). The cause of this behavior is in all probability the existence of rotational isomers. Raman polarization measurements at organosubstituted silicon di- and trihydrides demonstrate the accidental degeneracy of the SiH valence vibrations.     

Isotopic hydrogen exchange in σ-bonded ligand of σ-C6H5CH2MO(CO)3C5H5-π and σ-C6H5CH2W(CO)3C5H5-π complexes

Conclusions Quantitative data were obtained as the result of studying the kinetics of isotopic hydrogen exchange in aci medium in the-C₆H₅CH₂Mo(CO)₃C₅H₅- and-C₆H₅CH₂W(CO)₃C₅H₅- complexes, which characterize the CH₂M(CO)₃C₅H₅- substituents as being powerful electron donors.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1652–1654, July, 1973.     

Ein Titan(IV)-Komplex mit zwei koordinativ gebundenen Wassermolekülen: [(π-C5H5)2 Ti(H2O)2](NO3)2

A Titanium (IV) Complex with Two Coordinatively Bonded Water Molecules: [(π-C₅H₅)₂Ti(H₂O)₂](NO₃)₂ (π-C₅H₅)₂Ti(NO₃)₂ and H₂O react in acetone to form the diaquo complex [(π-C₅H₅)₂-Ti(H₂O)₂](NO₃)₂ ( A ). An X-ray analysis shows the titanium atom to be nearly tetrahedrally coordinated. Mean values of distances: Ti? O 2.01 Å, Ti? Z 2.03 Å (Z = center of ring); angles: O? Ti? O 92.7°, Z? Ti? Z 133.6°. Anions and cations are joined by hydrogen bonds to form strands that run in the direction of the crystallographic a axis. A crystallizes in the orthorhombic space group Pnma with Z = 4 and lattice parameters at ? 100°C a = 7.601(2), b = 13.458(4) and c = 13.139(4) Å.     

Syntheses and Anti—inflammatory Actiobn of （η—C5H5）2Ti （Cin）2 and （η—C5H5）2Ti（Tzea）2

Two new Complexes(Cp)2Ti(Cin)2and (CP2)Ti(Tzea)2(CP=Cyclopentadienyl η^5-C5H5)have been synthesized in THF by the reaction of HCin(Cincofen,2-phenylquinoline-4-carboxylic acid)or HTzea(5-phenyltetrazolyl-2-ethanoic acid)with(Cp)2TiCl2,and characterized by elemental analyses,IR,1H NMR and 13C NMR,UV spectra,molar conductivity,TGDTA.In the complexes the carboxyl groups are coordinated to Ti(IV)in a monodentate manner,The inhibitory actions of the complexes on mice ear tumefaction caused by croton oil and the rat foot granulation growth produced by cotton wool are higher than those of the corresponding ligands HCin,HTzea and [(Cp)2TiCl2],while their toxicities are lower than those of the free ligands.ηη     

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.