Zirconium-chelate and mono-?- cyclopentadienyl zirconium-chelate/ methylalumoxane systems as soluble Ziegler-Natta olefin polymerization catalysts

Janiak, Christoph; Lange, Katharina C. H.; Scharmann, Tobias G.

doi:10.1002/(sici)1099-0739(200006)14:6<316::aid-aoc990>3.0.co;2-u

Cited by 16 publications

(4 citation statements)

References 63 publications

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“…Known group 4 tris(pyrazolyl)borate complexes include halide, alkyl, alkoxide, 7d-g,, CO, acetoacetate, Cp, 9b,c cyclooctatetraenyl (COT), hydrazido, Tp 2 Ti, and imido derivatives . Recently, [tris(pyrazolyl)borate] halide and alkoxide complexes have been studied as catalysts for ethylene polymerization. 7g, Examples of group 4 tris(pyrazolyl)borate amido complexes are relatively rare . We have studied [tris(pyrazolyl)borate]M(NMe 2 ) 3 (M = Ti, Zr) complexes, in part to see whether they would be precursors to other tris(pyrazolyl)borate complexes.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Theoretical Studies of Group 4 Amido Hydrotris(pyrazolyl)borate Complexes

Cai

Lam

et al. 2003

Inorg. Chem.

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Titanium and zirconium amido complexes containing a hydrotris(pyrazolyl)borate (Tp) or hydrotris(3,5-dimethylpyrazolyl)borate (Tp*) ligand TpM(NMe(2))(3) (M = Ti, 1; M = Zr, 2) and Tp*M(NMe(2))(3) (M = Ti, 3; M = Zr, 4) were prepared by the reactions of M(NMe(2))(3)Cl (M = Ti, Zr) with sodium hydridotris(pyrazol-1-yl)borate and potassium hydridotris(3,5-dimethylpyrazol-1-yl)borate, respectively. The structures of 1, 2, and 4.CH(2)Cl(2) were determined by X-ray diffraction and show octahedral coordination geometry around the metal centers. Density functional theory calculations at the B3PW91 level were performed to understand the orientations and the rotational behavior of amido ligands in these metal complexes.

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Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Theoretical Studies of Group 4 Amido Hydrotris(pyrazolyl)borate Complexes

Cai

Lam

et al. 2003

Inorg. Chem.

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“…The use of cyclopentadienyl metal complexes, including metallocenes, for the generation of single-site olefin polymerization catalysts is now well established and is of considerable industrial interest . A more recent extension of this area has focused on the discovery of noncyclopentadienyl catalysts. , For example, attention has been directed towards the use of the N 3 donor [Tp R,R′ ] ligands, which belong to the same L 2 X covalent bond classification as cyclopentadienyl . As an illustration, both [Tp R,R′ ]ZrCl 3 and [Tp R,R′ ]Zr(CH 2 Ph) 3 , have been employed as precatalysts for olefin polymerization.…”

Section: Results and Discussionmentioning

confidence: 99%

Organometallic Zirconium Compounds in an Oxygen-Rich Coordination Environment: Synthesis and Structural Characterization of Tris(oxoimidazolyl)hydroboratozirconium Compounds

2018

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A series of tris(oxoimidazolyl)hydroborato ligands, which serve as LX [O] donors, have been employed to obtain organometallic zirconium compounds in an uncommon oxygen-rich coordination environment. For example, Cp[To]ZrCl has been synthesized via the reaction of [To]Na with CpZrCl and bears a structural resemblance to the bent metallocene dichloride derivative CpZrCl. In addition, the half-sandwich counterparts [To]ZrCl and [To]ZrCl have been obtained by metathesis of ZrCl with [To]Na and [To]Na, respectively. The structurally related zirconium benzyl compounds [To]Zr(CHPh) (R = Me, Bu, 1-Ad) have also been synthesized via the reactions of [To]Tl with Zr(CHPh), and X-ray diffraction studies demonstrate that the benzyl ligands in these compounds are conformationally flexible and exhibit a large range of Zr-CH-Ph bond angles (94.7-131.7°). Protolytic cleavage of one of the benzyl ligands of [To]Zr(CHPh) (R = Bu, 1-Ad) may be achieved by treatment with [PhNHMe][B(CF)] to generate {[To]Zr(CHPh)}[B(CF)], which are catalysts for the polymerization of ethylene. The molecular structure of the ether adduct, {[To]Zr(CHPh)(OEt)}[B(CF)], has been determined by X-ray diffraction. In addition to the use of tris(oxoimidazolyl)hydroborato ligands, bis(oxoimidazolyl)hydroborato ligands have also been used to obtain zirconium benzyl compounds in oxygen-rich environments, namely, [Bo]Zr(CHPh) and [Bo]Zr(CHPh).

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“…So far, some thermally stable non-metallocene complexes for olefin polymerization have been obtained through the utili-zation of ligands with multiple donor groups. For instance, Janiak and co-workers 79 reported that β-diketonato zirconium complexes bearing two different substituents on the α-position showed high catalytic activities for ethylene polymerization at 70 °C, which could meet and even exceed that of Cp 2 ZrCl 2 under the same conditions. Fujita's group 80 reported that, upon activation with MAO, a FI-type catalyst, [3-t Bu-2-(O)-C 6 H 3 CHvNPh] 2 TiCl 2 , was highly active in catalyzing ethylene polymerization (47 800 kg PE (mol-Ti h) −1 ) at 75 °C with n-heptane as the solvent.…”

Section: Introductionmentioning

confidence: 99%

High temperature ethylene polymerization catalyzed by titanium(iv) complexes with tetradentate aminophenolate ligands in cis-O, N, N chelating mode

et al. 2014

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A series of titanium trichloride complexes , ligated with claw-type tetradentate aminophenolate ligands were synthesized from the direct reaction of TiCl4(THF)2 with 1 equiv. of the corresponding aminophenol in the presence of triethylamine. For comparison purposes, titanium isopropoxide complexes were also synthesized via the reaction of Ti(O(i)Pr)4 and 1 equiv. of the proligand. Similar reactions of ZrCl4(THF)2 with the corresponding aminophenol ligands in the presence of triethylamine only allowed the isolation of zirconium complex . The X-ray diffraction studies reveal that titanium trichloride complexes , and titanium triisopropoxide complex all possess a distorted octahedral geometry with the tetradentate aminophenolate ligand in cis-O, N, N chelating mode, where the methoxy group of the aryl unit does not coordinate with the metal center in the solid state. Upon activation with MMAO, these titanium and zirconium(iv) complexes exhibited moderate to high catalytic activities for ethylene polymerization at 30-120 °C, producing high-molecular-weight polyethylenes with broad distributions (Mw/Mn = 10.2-34.8). The activities of titanium trichloride complexes are significantly higher than those of titanium isopropoxide and zirconium trichloride complexes at high temperatures. The highest activity of 15 456 kg (mol-Ti h)(-1) could be achieved by titanium trichloride complex with bromo groups on both ortho- and para-positions of the phenolate ring of the ligand at 120 °C.

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Zirconium-chelate and mono-?- cyclopentadienyl zirconium-chelate/ methylalumoxane systems as soluble Ziegler-Natta olefin polymerization catalysts

Cited by 16 publications

References 63 publications

Synthesis, Characterization, and Theoretical Studies of Group 4 Amido Hydrotris(pyrazolyl)borate Complexes

Synthesis, Characterization, and Theoretical Studies of Group 4 Amido Hydrotris(pyrazolyl)borate Complexes

Organometallic Zirconium Compounds in an Oxygen-Rich Coordination Environment: Synthesis and Structural Characterization of Tris(oxoimidazolyl)hydroboratozirconium Compounds

High temperature ethylene polymerization catalyzed by titanium(iv) complexes with tetradentate aminophenolate ligands in cis-O, N, N chelating mode

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