12129-06-5Relevant articles and documents
TRI-1-METHALLYL- AND 1-METHALLYL-BUTADIENE GROUP IV TRANSITION METAL COMPLEXES
Blenkers, J.,Meijer, H. J. de Liefde,Teuben, J. H.
, p. 383 - 394 (1981)
Reaction of Cp'MCl3 (Cp' = η5-C5(CH3)5; M = Ti, Zr, Hf) with 2-butenylmagnesium bromide at low temperatures gives Cp'M(1-methallyl)3, which is readily converted into Cp'M(η3-1-methallyl)(η4-butadiene) on heating.Only Cp'Hf(1-methallyl)3 could be isolated; it is fluxional and its NMR and IR spectra indicate that it consists of a complex mixture of isomers containing interconverting η1- and η3-1-methallyl groups.The compounds Cp'M(η3-C4H7)(η4-C4H6) are much more thermally stable; they show fluxional behaviour, but this is limited to theη3-1-methallyl group.These complexes are very reactive towards a large variety of organic substrates.
Facile functionalizations of permethyltitanocene dichloride to chiral persubstituted titanocene complexes
Pellny, Paul-Michael,Burlakov, Vladimir V.,Baumann, Wolfgang,Spannenberg, Anke,Horá?ek, Michal,Stěpni?ka, Petr,Mach, Karel,Rosenthal, Uwe
, p. 2816 - 2819 (2000)
The new class of compounds arising from unconventinal additions of 1, 4-disubstituted 1, 3-butadiynes to activated permethylmetallocene species of Ti and Zr can be used in facile functionalizations. For example, the chiral product 5, obtained from the addition of tBuC=CC=CtBu to activated permethyltitanocene, has been derivatized by simple means, e.g., hydrogen chloride, bromine, or dihydrogen, affording practically useful functionalized titanocene compounds containing a chiral auxiliary ligand with an intramolecularly coordinated (compound 7) or a free double bond (compounds 8a, b). The new complexes have been characterized spectroscopically. Additionally, X-ray crystal structure analyses were performed for 7 and 8a, b.
Reactivity of functionalised decamethyltitanocenes: Synthesis and structure of chiral monocyclopentadienyl titanium halogenides
Burlakov, Vladimir V.,Lyssenko, Konstantin A.,Spannenberg, Anke,Baumann, Wolfgang,Arndt, Perdita,Shur, Vladimir B.,Rosenthal, Uwe
, p. 76 - 80 (2013)
The recently described unconventional substituted titanocene complex [Cpa -Ti{η5-C5Me3(CH 2-CH(tBu)-η2-C2-CH(tBu)-CH2)}] (1) can be derivatised by simple means (Br2, HX with X = Cl, Br) to generate the titanocene dihalogenides 2-Br, 2-Cl, which give in a subsequent reaction besides Cpa&-TiX3 (3-Br: X = Br, 3-Cl: X = Cl) the titanium complexes 4-Cl resp. 4-Br with one functionalised chiral cyclopentadienyl ligand. In the reaction of 1 with Et3N·3HF an analogous isostructural titanocene dihalogenide 2-F as well as the unusual dimeric anionic heptafluoride 5 are formed. All complexes have been characterised spectroscopically, and X-ray crystal structure determinations were performed for 4-Cl and 2-F.
The Puzzling Monopentamethylcyclopentadienyltitanium(III) Dichloride Reagent: Structure and Properties
García-Castro, María,García-Iriepa, Cristina,Del Horno, Estefanía,Martín, Avelino,Mena, Miguel,Pérez-Redondo, Adrián,Temprado, Manuel,Yélamos, Carlos
, (2019)
Following the track of the useful titanocene [Ti(η5-C5H5)2Cl] reagent in organic synthesis, the related half-sandwich titanium(III) derivatives [Ti(η5-C5R5)Cl2] are receiving increasing attention in radical chemistry of many catalyzed transformations. However, the structure of the active titanium(III) species remains unknown in the literature. Herein, we describe the synthesis, crystal structure, and electronic structure of titanium(III) aggregates of composition [{Ti(η5-C5Me5)Cl2}n]. The thermolysis of [Ti(η5-C5Me5)Cl2Me] (1) in benzene or hexane at 180 °C results in the clean formation of [{Ti(η5-C5Me5)Cl(μ-Cl)}2] (2), methane, and ethene. The treatment of 1 with excess pinacolborane in hexane at 65 °C leads to a mixture of 2 and the paramagnetic trimer [{Ti(η5-C5Me5)(μ-Cl)2}3] (3). The X-ray crystal structures of compounds 2 and 3 show Ti-Ti distances of 3.267(1) and 3.219(12) ?, respectively. Computational studies (CASPT2//CASSCF and BS DFT methods) for dimer 2 reveal a singlet ground state and a relatively large singlet-triplet energy gap. Nuclear magnetic resonance spectroscopy of 2 in aromatic hydrocarbon solutions and DFT calculations for several [{Ti(η5-C5Me5)Cl2}n] aggregates are consistent with the existence of an equilibrium between the diamagnetic dimer [{Ti(η5-C5Me5)Cl(μ-Cl)}2] and a paramagnetic tetramer [{Ti(η5-C5Me5)(μ-Cl)2}4] in solution. In contrast, complex 2 readily dissolves in tetrahydrofuran to give a green-blue solution from which blue crystals of the mononuclear adduct [Ti(η5-C5Me5)Cl2(thf)] (4) were grown.
Reactions of Organotitanoxane Fluorides with AlR3 (R = Me, Et, CH2Ph) and Me3SiCl: X-ray Crystal Structures of [C5Me5Ti(μ-O)]4F[(μ-F)AlMe 3]3, [C5Me5Ti(μ-O)]4F 3[(μ-F)Al(CH2Ph)3]
Yu, Peihua,Pape, Thomas,Uson, Isabel,Said, Musa A.,Roesky, Herbert W.,Montero, Mavis L.,Schmidt, Hans-Georg,Demsar, Alojz
, p. 5117 - 5124 (1998)
A new pentamethylcyclopentadienyl titanoxane fluoride (C5Me5)4Ti4O5F 2 (1b) has been synthesized from (C5-Me5)4Ti4O5Cl 2 using the fluorinating reagent Me3SnF. The fluorination of organotitanoxane chlorides proceeds via a proposed intermediate similar to the four-membered ring Ti(μ-Cl)(μ-F)Sn and the bridged Ti(μ-F)ClSnMe3 species. The reactions of 1b and [C5Me5Ti(μ-O)F]4 with AlR3 (R = Me, Et, CH2Ph) afforded the thermally unstable adducts [C5Me5Ti(μ-O)]4F 4-n[(μ-F)AlR3]n (n = 1-4), which proceed with selective exchange of fluorine atoms for alkyl groups to give an eight-membered alkylated ring compound [C5Me5Ti(μ-O)R]4. The reactions of 1b and [C5Me5Ti(μ-O)F]4 with Me3SiCl result in exchange of fluorine for chlorine atoms. Moreover, using an excess of Me3SiCl leads to a novel oxygen-chlorine exchange reaction to give C5Me5Ti(μ-O)]4F[(μ-F)AlMe 3]3 . The crystal structures of complexes (C5Me5)4Ti4O5X 2 (X = Cl (1a), F (1b)), [C5Me5Ti(μ-O)]4F[(μ-F)AlMe 3]3 (2b), [C5Me5Ti(μ-O)]4F 3[(μ-F)Al(CH2Ph)3] (3a), and [C5Me5Ti(μ-O)Et]4 (4) have been determined by X-ray diffraction studies, Both chlorides and fluorides in 1a and Ib, respectively, are oriented to the exo position of their butterfly structures. The bond lengths of the terminal fluorines (Ti-Ft) in compounds 2b and 3a are discussed with respect to the deviation from the bond lengths of the bridging fluorines (Ti-Fb-Al). The structure of 4 displays a nonplanar Ti4O4 ring conformation as shown in 2b and 3a.
(C5Me5)SiMe3 as a mild and effective reagent for transfer of the C5Me5 ring: an improved route to monopentamethylcyclopentadienyl trihalides of the group 4 elements
Llinas, Gerardo Hidalgo,Mena, Miguel,Palacios, Federico,Royo, Pascual,Serrano, Ricardo
, p. 37 - 40 (1988)
The reaction between (C5Me5)SiMe3 and group 4 element tetrahalides MX4 (M=Ti, X=Cl, Br, I; M=Zr and Hf, X=Cl) gives the corresponding (η5-C5Me5)MX3 derivatives in nearly quantitative yields in a one-step procedure without the need for further purification.
Influence of ligands and cocatalyst on the activity in ethylene polymerization of soluble titanium complexes
Conti, Giuseppe,Arribas, Guillermo,Altomare, Angelina,Ciardelli, Francesco
, p. 41 - 50 (1994)
Known and new titanium complexes bearing alkoxy, phenoxy, carboxylate and cyclopentadienyl ligands in addition to chlorine have been tested towards ethylene polymerization after activation with aluminum alkyls (AlR3) or methylalumoxane (MAO). In the absence of cyclopentadienyl ligands the optimal productivity obtained is very similar either with AlR3 or MAO, but higher MAO/Ti than AlR3/Ti ratios are necessary. In the case of complexes with the Cp ligand much better productivity can be obtained with high MAO ratios thus confirming that under these conditions a different activation mechanism is operative.
Cleavage of Dinitrogen from Forming Gas by a Titanium Molecular System under Ambient Conditions
González-Moreiras, Mariano,Mena, Miguel,Pérez-Redondo, Adrián,Yélamos, Carlos
supporting information, p. 3558 - 3561 (2017/03/20)
Simple exposure of a hexane solution of [TiCp*Me3] (Cp=η5-C5Me5) to an atmosphere of commercially available and inexpensive forming gas (H2/N2 mixture, 13.5–16.5 % of H2) at room temperature leads to the methylidene–methylidyne–nitrido cube-type complex [(TiCp*)4(μ3-CH)(μ3-CH2)(μ3-N)2] via dinitrogen cleavage. This paramagnetic compound reacts with [D1]chloroform to give the titanium(IV) methylidyne–nitrido species [(TiCp*)4(μ3-CH)2(μ3-N)2], whereas its one-electron oxidation with AgOTf or [Fe(η5-C5H5)2](OTf) (OTf=O3SCF3) yields the diamagnetic ionic derivative [(TiCp*)4(μ3-CH)(μ3-CH2)(μ3-N)2](OTf). The μ3-nitrido ligands of the methylidyne–nitrido cubane complex can be protonated with [LutH](OTf) (Lut=2,6-lutidine) or hydrogenated with NH3?BH3 to afford μ3-NH imido moieties.
Highly efficient one-step direct synthesis of monocyclopentadienyltitanium complexes
Zhang, Yuetao,Mu, Ying
, p. 631 - 634 (2008/10/09)
This report describes a highly efficient one-step synthetic strategy for monocyclopentadienyltitanium complexes by the direct reaction of TiCl 4 with substituted cyclopentadienes, without adding any other reagents. This new synthetic method is particularly efficient for cyclopentadienes with a pendant group that can bond or coordinate to the Ti atom.
New titanatranes: Characterization and styrene polymerization behavior
Kim, Youngjo,Han, Yonggyu,Hwang, Jeong-Wook,Kim, Myong Woon,Do, Youngkyu
, p. 1127 - 1135 (2008/10/08)
New titanatranes containing cyclopentadienyl ligands were prepared by the reactions of various kinds of trialkanolamines with (C5Me4R)TiCl3 (Cp′ = C5Me4R) in the presence of triethylamine. The X-ray analyses reveal that they exist in the monomeric form in the solid state and the Ti atom adopts essentially an η5 bonding posture with the Cp′ ring and a tetradentate bonding mode with the trialkanolatoamine ligand via a transannular interaction from the bridgehead N atom to Ti. All compounds show very high catalytic activity for the syndiospecific polymerization of styrene in the presence of modified methylaluminoxane (MMAO) cocatalyst.
