1270-98-0Relevant articles and documents
Holliday, A. Kenneth,Makin, Paul H.,Puddephatt, Richard J.
, (1979)
Living organotitanium(IV)-catalyzed polymerizations of isocyanates
Patten, Timothy E.,Novak, Bruce M.
, p. 1906 - 1916 (1996)
An organotitanium(IV) compound, TiCl3OCH2CF3, 1, was found to polymerize n-hexyl isocyanate to high yields and without the formation of cyclic trimer. CpTiCl2L (L = -OCH2CF3, -N(CH3)2, -CH3), 2-4, respectively, likewise polymerized n-hexyl isocyanate but also polymerized isocyanates in the presence of donor solvents and isocyanates possessing donor functional groups, activated olefins, and strained olefins. The activity of the organotitanium(IV) catalysts decreased with increasing steric bulk about the metal center and increasing electron donation to the metal center from the ligands. The polymerization of n-hexyl isocyanate using organotitanium(IV) compounds is living. The PDIs of PHIC synthesized using catalysts 1-4 were found to range from 1.05 to 1.2. The molecular weight of the polymer formed in polymerizations of n-hexyl isocyanate using catalysts 1-4 varied linearly as a function of the monomer-to-initiator ratio and the percent conversion of the polymerization. Polymerizations using 2 can be endcapped quantitatively, and well-defined block copolymers can be synthesized using catalysts 1-4. The kinetics for polymerizations using catalysts 1 and 2 are first-order in both monomer and catalyst (k1 = 8.5 x 10-4 mol L-1 s-1, k-1 = 3.8 x 10-4 s-1). The active endgroup of a polymerization using 3 was observed using IR spectroscopy, and the frequency of the IR stretch (1548 cm-1) was consistent with an η2-amidate endgroup structure. Finally, the kinetic data for the polymerization of n-hexyl isocyanate and the known chemistry of CpTiCl2L compounds were found to be consistent with a propagation step that occurs via a bifunctional activation mechanism.
LITHIUM NITRIDE REDUCTION OF Cp2TiCl2 and CpTiCl3: THE SYNTHESIS OF (Cp2TiCl)2, (Cp2TiCl2)n, Cp2Ti(CO)2 AND CHLOROTETRATITANIUM AND NITRIDOHEXATITANIUM COMPLEXES
Kilner, Melvyn,Parkin, Gerard
, p. 181 - 192 (1986)
Stoichiometric reactions of Cp2TiCl2 or CpTiCl3 with Li3N in various molar ratios result in reduction to (Cp2TiCl)2, (CpTiCl2)n and (CpTiCl)4 and provide useful synthetic routes.Further reduction produces hexanuclear nitrido titanium clusters,
The synthesis and electrochemistry of CpTiCl2(OR) (R = alkyl, aryl) complexes
Fussing, Ingrid M. M.,Pletcher, Derek,Whitby, Richard J.
, p. 109 - 118 (1994)
The syntheses of several new CpTiCl2(OR) (R = alkyl, aryl) complexes are described.It was possible to isolate pure product when the R group is substituted such as to cause steric crowding at the metal centre; for example, particularly good yields of the p
Synthesis and characterization of cyclopentadienyl titanium trichloride and indenyltitanium trichloride; monocyclictitanium trihalide complexes
Masnadi, Mitra,Jamjah, Roghieh,Ahmadjo, Saeed,Nekoomanesh, Mehdi
, p. 543 - 547 (2006)
CpTiCl3 and IndTiCl3 are homogeneous metallocene catalysts that are produced under highly controlled conditions. Syndiotactic polymerization of styrene is carried out using these catalysts while methylaluminoxane (MAO) is used as a cocatalyst. In the present paper synthesis of CpTiCl3 was examined at first by reacting TiCl4 with CpNa, this reaction just led to formation of Cp2TiCl2 so CpNa was not a suitable Cp donor compound, therefore CpSiMe3 was used instead of CpNa. Reaction of CpSiMe3 with TiCl4, produced CpTiCl3 immediately. IndTiCl3 was synthesized by reacting IndSiMe3 and TiCl4 as well. At the end two synthetic catalysts were characterized by FTIR and 1H-NMR spectrometers. Copyright
HYDROMETALLATION OF 1-OCTENE WITH GRIGNARD REAGENTS, ALKYLMAGNESIUMS AND ALKYLMAGNESIUM HYDRIDES CATALYZED BY DICYCLOPENTADIENYLTITANIUM DICHLORIDE
Ashby, E. C.,Ainslie, Richard D.
, p. 1 - 12 (1983)
The hydrometallation of 1-octene by a series of Grignard reagents (EtMgCl, EtMgBr, n-PrMgCl, i-PrMgCl, n-BuMgCl, sec-BuMgCl, iso-BuMgCl, iso-BuMgBr and iso-BuMgI), dialkylmagnesium compounds (Me2Mg, Et2Mg, n-Pr2Mg, iso-Pr2Mg, n-Bu2Mg, sec-Bu2Mg, iso-Bu2Mg and t-Bu2Mg), alkylmagnesium hydrides (RMgH, where R = Me, Et, t-Bu, Cp and Ph) and magnesium hydrides (MgH2, HMgCl and HMgBr) in the presence of 5 molpercent dicyclopentadienyltitanium dichloride (Cp2TiCl2) in THF has been investigated.The percent yield of octane (produced on hydrolysis of the product) vs. time was plotted for several reactions in order to compare the effect of individual reagents.Most alkylmagnesium compounds with β hydrogen atoms gave primarily the hydrometallation product, although t-Bu2Mg produced isomerized starting material.MeMgH gives the best yield of octane on hydrolysis of the reaction mixture.A mechanism is proposed which accounts for all observations.
Bildung von μ-Oxo-bis(ν5-cyclopentadienyldichlorotitan(IV)) aus η5-Cyclopentadienyl-tris(methylselenolato)titan(IV)
Gowik, Petra,Klapoetke, Thomas,Pickardt, Joachim
, p. 343 - 348 (1990)
The recrystallization of CpTi(SeCH3)3 (1) from methylene chloride/pentane (1:1) in the presence of traces of moisyure over a period of 18 monaths at -18 deg C afforded the species 2O (2a) (65percent), CpTiCl3 (2b) (10percent) and 2 (2c)
Steric influences in cyclopentadienyl-monophenoxide complexes of titanium(iv) arising from ortho-substitution of the phenoxide ligand
Nielson, Alastair J.,Harrison, John A.,Shen, Chaohong,Waters, Joyce M.
, p. 1729 - 1736 (2008/10/09)
Reaction of [CpTiCl3] with 1 equiv. of Me3SiOC6H4CMe3-4 in benzene or thermalisation with an excess of neat Me3SiOC6H4CMe3-4 gives good yields of crystalline [CpTiCl2(OC6H4CMe3-4)] (1) for which an X-ray crystal structure determination shows a distorted tetrahedral geometry. Reaction of [CpTiCl3] and Me3SiOC6H3CMe3-2-Me-4 via the benzene solvent method or the direct thermalisation gives rise to crystalline [CpTiCl2(OC6H3CMe3-2-Me-4)] (2) for which an X-ray crystal structure determination shows a distorted tetrahedral geometry little changed from complex 1 but with the phenoxide ligand ring rotated so that two of the tert-butyl group methyls straddle one chloro ligand. Refluxing [CpTiCl3] and Me3SiOC6H4Ph-4 in toluene gave crystalline [CpTiCl2(OC6H4Ph-2)] (3) which X-ray crystallography shows has a distorted tetrahedral geometry little changed from 1 or 2. The phenoxide ligand ring is rotated less in 1 than in 2 or 3 with the 2-phenyl substituent sited between the chloro and Cp ligands. The complexes differ only in the interplanar angle between the Cp and phenoxide ligand phenyl rings [6.4(1)° for 1, 29.4(1)° for 2 and 22.2(1)° for 3]. DFT calculations carried out on 2 are in good agreement with the X-ray crystal structure. A relaxed PES scan shows that the tert-butyl group in the complex cannot freely rotate past the adjacent chloro ligand and is essentially locked in close proximity to it. There is a shallow minimum (2 kJ/mol within a range of 60 degrees) for the Ti-O-C-C dihedral angle indicating there is sufficient torsional motion within the molecule to accommodate the tert-butyl group in the observed position.
Structural studies of complexes of vanadium(III) and titanium(IV) with N,N-dimethylaminoniethylferrocenyl
Hitchcock, Peter B.,Hughes, David L.,Leigh, G. Jeffery,Sanders, J. Roger,De Souza, Jaisa S.
, p. 1161 - 1173 (2007/10/03)
Vanadium(III) and titanium(IV) complexes containing 12-16 valence-shell electrons have been synthesised by treatment of cyclopentadienylmetal halides with the lithium salt of N,N-dimethylaminomethylferrocene, Li(FcN). The structurally characterized products were [(η5-C5H5)2Ti(η 1-FcN)Cl] 1, [(η5-C5H5)Ti(FcN)xCl3 -x)] (x = 1, complex 2; x = 2, complex 3; and x = 3, complex 4) and [V(FcN)2Cl] 6. They contain FcN bound either monodentate, through the aromatic 2-carbon atom, or bidentate, through that carbon and the amine nitrogen. Despite employing a variety of spectroscopic techniques, we were unable to distinguish the mode of binding in any way other than a crystal structure analysis. Compound 4 changes spontaneously at room temperature into the structurally characterised [(η5-C5H5)Ti(FcN)(FcN′)] 5. The ligand FcN′ arises by metallation of one methyl group of one FcN in 4 with elimination of H(FcN). This kind of metallation has not been recognised hitherto in titanium or vanadium FcN chemistry, and it may explain why yields of required products are sometimes very low. The synthetic and structural versatility of the ligand FcN have been clearly demonstrated.
