Synthesis and properties of a thermally stable methyltitanium(IV) compound: Cyclopentadienylmethyldichlorotitanium(IV)

Erskine, Gordon J.; Hurst, Graham J.B.; Weinberg, E.; Hunter, Brian K.; McCowan, James D.

doi:10.1016/0022-328x(84)80197-7

Cited by 24 publications

(6 citation statements)

References 10 publications

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“…The monoalkylation product (Cat)B−CpTiCl 2 (Me) ( 7 ) is formed exclusively, even when the reaction is carried out in the presence of 5 equiv of dimethylzinc. Similar reactivity with dimethylzinc has been reported for the parent complex CpTiCl 3 and has been confirmed by us.…”

Section: Resultssupporting

confidence: 90%

New Examples of Half-Sandwich (Borylcyclopentadienyl)titanium Trichloride Complexes and an X-ray Structural Characterization of the Homobimetallic Complex [TiCl₃{η⁵-C₅H₄}]₂BPh

et al. 1996

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A new series of half-sandwich (borylcyclopentadienyl)titanium trichloride complexes have been prepared which include the boryl substituents [1,2-(C6H4O2)]B−, Ph(Cl)B−, Ph2B− and a (PhB<)-bridged bimetallic complex. No correlation was found between the 1H and 13C NMR chemical shifts of the cyclopentadienyl ring in these complexes and the Lewis acidity of the attached boryl group. The crystal structure of the phenylboron-bridged bimetallic complex PhB{(η5-C5H4)TiCl3}2 was determined. The cyclopentadienyltitanium units of the molecule are twisted away from each other, forming an angle of 41° between the cyclopentadienyl ring planes. Each cyclopentadienyl ring is twisted out of the trigonal plane of the boron by 24°. Preliminary results concerning the Ti-alkylation of some of these complexes are described.

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Section: Resultssupporting

confidence: 90%

New Examples of Half-Sandwich (Borylcyclopentadienyl)titanium Trichloride Complexes and an X-ray Structural Characterization of the Homobimetallic Complex [TiCl₃{η⁵-C₅H₄}]₂BPh

et al. 1996

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“…Combustion analyses were performed by Galbraith Laboratories Inc., Knoxville, TN, or E + R Microanalytical Laboratory, Corona, NY. CpTiCl 2 Me, [CpTi(OC 6 H 3 -2,6- i -Pr 2 )(μ-S)] 2 ( 1 ), CpTi(OC 6 H 3 -2,6- i -Pr 2 )(SBn) 2 ( 2 ), CpTi(OC 6 H 3 -2,6- i -Pr 2 )(SEt) 2 , CpTi(OC 6 H 3 -2,6- i -Pr 2 )(SBn)Cl ( 3 ), and CpTi(OC 6 H 3 -2,6- i -Pr 2 )Cl 2 were prepared via published methods …”

Section: Methodsmentioning

confidence: 99%

Thermal Reactions of Titanium Thiolates: Terminal Titanium Sulfides in CS Bond Cleavage Reactions

1998

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The thermolysis of monocyclopentadienyltitanium thiolate complexes leads to ligand redistributions and C-S bond cleavage reactions. Kinetic study of the C-S bond thermolysis reaction of CpTi(OC 6 H 3 -2,6-i-Pr 2 )(SBn) 2 (2) to the sulfide-bridged dimer [CpTi(OC 6 H 3 -2,6i-Pr 2 )(µ-S)] 2 (1) is shown to be first order in 2, consistent with an intramolecular process proceeding via a terminal sulfide intermediate and rapid dimerization (k ) 2.8 × 10 -6 s -1 ). The related species CpTi(OC 6 H 3 -2,6-i-Pr 2 )(SBn)Cl (3), CpTi(OC 6 H 3 -2,6-i-Pr 2 )(SMe) 2 (4), and CpTi(OC 6 H 3 -2,6-i-Pr 2 )(SPh) 2 (5) are thermally stable, although compounds 4 and 5 undergo thermally induced ligand redistribution reactions. These redistribution reactions are thought to occur via a dimeric intermediate in which bridging thiolate ligands are exchanged between two metal centers. A dimeric intermediate is supported by the characterization of the species [CpTi(SR) 2 (µ-SR)] 2 (R ) Et (7), Bn (8)) which are dimeric in solution at low temperature and in the solid state. In contrast, Cp*Ti(SBn) 3 ( 9) is monomeric. Efforts to intercept a terminal sulfide intermediate in the formation of 1 were unsuccessful, although reaction of CpTiCl 2 Me with LiSBn in the presence of PMe 3 gives [CpTiCl(µ-S)] 2 [PMe 3 Bn] (10) in low yield. The analogue of 2, Cp*Ti(OC 6 H 3 -2,6-i-Pr 2 )(SBn) 2 , 12, is thermally stable; however, thermolysis of Cp*TiCl(SBn) 2 gave [Cp*TiCl(µ-S)] 2 (13). Ultimately, the LiCl adduct of a terminal sulfide species Cp*Ti(OC 6 H 3 -2,6-i-Pr 2 )(µ-S)(µ-Cl)Li(THF) 2 ( 14) was isolated from the reaction of Cp*Ti(OC 6 H 3 -2,6-i-Pr 2 )Cl 2 (11) with Li 2 S. Treatment of ( 14) with PMe 3 generates the monomeric terminal sulfide complex species Cp*Ti(OC 6 H 3 -2,6-i-Pr 2 )(S)(PMe 3 ) (15), which is unstable, slowly evolving PMe 3 affording [Cp*Ti(OC 6 H 3 -2,6-i-Pr 2 )(µ-S)] 2 (16). Compound 16 is also obtained directly by heating solutions of 14. Crystallographic studies of 8, 10, 12, 13, 14, and 16 are reported herein. The intermediacy of terminal metal sulfides in C-S processes are discussed. species by sulfur. C-S bond cleavage is an alternative route to M-S bond formation. The research groups of Winter 12 and Bochmann 13 have produced TiS and TiS 2 films from titanium thiolate precursors. In an analogous manner, M-S aggregates as Zr 3 S 3 (t-BuS) 2 (BH 4 ) 4 -(THF) 2 and Zr 6 S 6 (t-BuS) 4 (BH 4 ) 8 (THF) 2 , 14 Zr 3 S(S-t-Bu) 10 , 15 (CpTi) 4 (µ 3 -S) 3 (µ 2 -S)(µ 2 -SEt) 2 , (CpTi) 6 (µ 3 -S) 4 (µ 3 -O) 4 , 16 and [(CpTi(OC 6 H 3 -2,6-i-Pr 2 )(µ 3 -S)] 3 TiCp 17 have been prepared via C-S bond thermolysis reactions. Some of the more recent examples are depicted in Scheme 1. More recently, we have described the high-yield thermolysis of CpTi(OC 6 H 3 -2,6-i-Pr 2 )(SBn) 2 (2) to the sulfide-bridged dimer [CpTi(OC 6 H 3 -2,6-i-Pr 2 )(µ-S)] 2 (1). 17 Unlike the complex reactions affording larger M-S aggregates, the reactions of discrete monocyclopentadienyltitanium thiolate complexes, a class of compounds that has drawn little ...

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“…CpTiCl 2 CH 3 , 4. This compound was prepared using a modification of the procedure of Erskine et al In a 50 mL Schlenk flask, CpTiCl 3 (0.503 g, 2.29 mmol) was dissolved in 25 mL of THF. The flask was cooled to 0 °C with an ice bath, and then 0.760 mL of a 3.0 M solution of MeMgCl in THF was added dropwise via syringe over a 1 h period.…”

Section: Methodsmentioning

confidence: 99%

“…Sublimation at 50 °C and 0.01 Torr onto a dry ice/isopropyl alcohol cold finger afforded 0.157 g (34% yield) of orange crystals: mp = steadily decomposed upon heating; 1 H NMR (400 MHz, toluene- d 8 ) δ (ppm) 5.90 (s, 5H), 1.71 (s, 3H) (lit. (benzene- d 6 ) 5.87, 1.74); 13 C{ 1 H} NMR (100 MHz, toluene- d 8 ) δ (ppm) 118.89, 79.65; IR (thin film) 3104 (s), 2974 (m), 2868 (m), 1863 (w), 1778 (w), 1682 (w), 1437 (s), 1389 (w), 1438 (w), 1389 (w), 1094 (sh), 1066 (m), 1019 (m), 910 (w), 835 (s), 792 (m), 708 (w) cm -1 . Anal.…”

Section: Methodsmentioning

confidence: 99%

Living Organotitanium(IV)-Catalyzed Polymerizations of Isocyanates

1996

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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 (k 1 = 8.5 × 10-4 mol L-1 s-1, k - 1 = 3.8 × 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.

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Synthesis and properties of a thermally stable methyltitanium(IV) compound: Cyclopentadienylmethyldichlorotitanium(IV)

Cited by 24 publications

References 10 publications

New Examples of Half-Sandwich (Borylcyclopentadienyl)titanium Trichloride Complexes and an X-ray Structural Characterization of the Homobimetallic Complex [TiCl₃{η⁵-C₅H₄}]₂BPh

New Examples of Half-Sandwich (Borylcyclopentadienyl)titanium Trichloride Complexes and an X-ray Structural Characterization of the Homobimetallic Complex [TiCl₃{η⁵-C₅H₄}]₂BPh

Thermal Reactions of Titanium Thiolates: Terminal Titanium Sulfides in CS Bond Cleavage Reactions

Living Organotitanium(IV)-Catalyzed Polymerizations of Isocyanates

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Synthesis and properties of a thermally stable methyltitanium(IV) compound: Cyclopentadienylmethyldichlorotitanium(IV)

Cited by 24 publications

References 10 publications

New Examples of Half-Sandwich (Borylcyclopentadienyl)titanium Trichloride Complexes and an X-ray Structural Characterization of the Homobimetallic Complex [TiCl3{η5-C5H4}]2BPh

New Examples of Half-Sandwich (Borylcyclopentadienyl)titanium Trichloride Complexes and an X-ray Structural Characterization of the Homobimetallic Complex [TiCl3{η5-C5H4}]2BPh

Thermal Reactions of Titanium Thiolates: Terminal Titanium Sulfides in CS Bond Cleavage Reactions

Living Organotitanium(IV)-Catalyzed Polymerizations of Isocyanates

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New Examples of Half-Sandwich (Borylcyclopentadienyl)titanium Trichloride Complexes and an X-ray Structural Characterization of the Homobimetallic Complex [TiCl₃{η⁵-C₅H₄}]₂BPh

New Examples of Half-Sandwich (Borylcyclopentadienyl)titanium Trichloride Complexes and an X-ray Structural Characterization of the Homobimetallic Complex [TiCl₃{η⁵-C₅H₄}]₂BPh