1270-98-0Relevant articles and documents
Preparation of metallacyclic titanocene hydrocarbyl complexes and their use in propene polymerization reactions
Erker, Gerhard,Korek, Uwe,Petrenz, Ralph,Rheingold, Arnold L.
, p. 215 - 231 (1991)
A series of differently-substituted bis(cyclopentadienyl)titanaindan complexes has been prepared, characterized, and employed as transition metal components of homogeneous titanocene/alumoxane Ziegler-type catalysts for propene polymerization reactions.The titanaindan systems 3a and 3b were synthesized via an aryne titanocene intermediate by means of thermolysis of Cp2TiPh2 (1a) or (H3CC5H4)2TiPh2 (1b) in the presence of ethylene.The analogous reactions of 1a, b with propene, 1-pentene or 1-decene gave the corresponding 3-substituted 1,1-bis(cyclopentadienyl)titanaindan systems (4a-d).The t-butyl Cp-substituted diphenyltitanocene complexes CpTiPh2 (1c) and 2TiPh2 (1d) reacted in a different way.Their thermolysis proceeded cleanly by means of intramolecular C-H activation at the t-butyl substituent by the reactive aryne ligand to give the metallacyclic systems (RC5H4)Ph (5) (a: R = H; b: R = CMe3).The titanaindan complex 3a has been characterized by X-ray diffraction.
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.
REACTIONS OF TRIMETHYLSILYLCYCLOPENTADIENE DERIVATIVES WITH TITANIUM, NIOBIUM, AND TANTALUM HALIDES
Cardoso, Ana M.,Clark, Robin J. H.,Moorhause, Stephen
, p. 1156 - 1160 (1980)
The use of trimethylsilyl derivatives as effective reagents for the new or improved syntheses of complexes of the early transition metals is described.Improved routes, involving the use of trimethylsilylcyclopentadiene, are described for the syntheses of , , , , and (cp=cyclopentadienyl).Routes, involving the use of bis(trimethylsilyl)cyclopentadiene, are described for the syntheses of the analogous complexes , where X=Cl, Br, or I.The reactions of , , and with a variety of bidentate ligands are described.The Lewis acidity of these titanium compounds is much reduced from that of the parent tetrahalides and only two adducts have been positively identified: these are *phen (phen=o-phenanthroline) and *pdma (pdma=o-phenylenebisdimethylarsine).
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,
MONOALKYL- AND MONOARYL-AMIDOTITANIUM COMPLEXES
Jekel-Vroegop, C. T.,Teuben, J. H.
, p. 309 - 316 (1985)
A series of new monoalkyl- and monoaryl-amido complexes, CpTiCl2NHR (R=Et, i-Pr, t-Bu, Ph), has been synthesized and characterized.They were made in essentially quantitative yields by a very convenient reaction of CpTiCl3 with Me3SiNHR.The new complexes yield NMR and IR spectroscopic data for monoalkylamido complexes, such data being previously scarce.The compounds have very reactive amido hydrogen atoms, as is demonstrated by their thermal decomposition and their reaction with (Lewis) bases such as amines or organoalkali compounds.The products are the new bridged imido complexes, (CpTiCl)2(μ-NR)2.
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
Recycling titanocene dichloride from the petasis methylenation reaction
Berget, Patrick E.,Schore, Neil E.
, p. 552 - 553 (2006)
A simple method for recycling the titanium species used in the Petasis methylenation reaction is described. Treatment of the titanocene oxide byproduct with chlorotrimethylsilane and pyridine allows regeneration, recovery, and successful reuse of titanocene dichloride in amounts corresponding to nearly 90% of the dimethyltitanocene reagent initially employed.
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
New Amido- and Imido-titanium Complexes
Vroegop, Christina T.,Teuben, Jan H.,Bolhuis, Fre van,Linden, Johannes G. M. van der
, p. 550 - 552 (1983)
cpTiCl3 (cp=η5-C5H5) in reaction with Me3SiN(H)R (R=Et, iPr, tBu, or Ph) yields the amido complexes cpTi(Cl)2N(H)R, which react further by HCl abstraction to give the corresponding centrosymmetric binuclear imido complexes 2(μ-RN)2; s
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.
