Biphenylene-Bridged Dinuclear Group 4 Metal Complexes:  Enhanced Polymerization Properties in Olefin Polymerization

Lee, Min Hyung; Kim, Seong Kyun; Do, Youngkyu

doi:10.1021/om049316w

Cited by 42 publications

(19 citation statements)

References 23 publications

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“…In this regard, our group recently reported the well-defined dinuclear group 4 metal complexes [4,4Ј- (3a), which are linked by a rigid biphenylene bridge, and the direct comparison of their catalytic properties with those of the corresponding mononuclear analogues in ethylene and styrene polymerization. [27] We observed an increase of both molecular weight of polymer and catalytic activity, irrespective of the co-catalyst employed, especially in ethylene polymerization.…”

Section: Introductionmentioning

confidence: 69%

“…[27] These ligands are poorly soluble in common organic solvents but are more soluble than 1a, thus reflecting their flexible nature. The zirconium complexes 2b and 2c were prepared in a straightforward manner Scheme 1.…”

Section: Complexes Synthesis and Characterizationmentioning

confidence: 99%

“…The detailed structural analysis indicates that the bonding geometry around the zirconium center, such as the Cl(1)-Zr-Cl(2) and Cg(1)-Zr-Cg(2) bond angles and Zr-Cl and Zr-Cg bond lengths shown in Table 1, are in a similar range to those of mononuclear, unbridged zirconocene complexes. [28][29][30] The dihedral angle of 41.28(18) nonuclear zirconocene 4a (47.2°) [31] than that observed in the biphenylene-bridged 2a [63.6(2)°], [27] which suggests that flexible nature of the bridging group makes the steric environment of each metallocene unit of 2b similar to that of the mononuclear 4a. [a] Data taken from ref.…”

Section: X-ray Crystallographic Structures Of 2b and 3bmentioning

confidence: 99%

“…[a] Data taken from ref. [27] [b] Cg(1) and Cg (2) The titanium complex 3b crystallizes in the space group C2/c and contains half of each of two independent molecules in the asymmetric unit. Similarly to 2a and 3a, two CpЈTiCl 3 (CpЈ = C 5 Me 4 Ph) fragments are also perfectly inverted with respect to the C(16)-C(16Ј) bond axis, thus indicating that complex 3b consists of two equivalent units in the solid state.…”

Section: X-ray Crystallographic Structures Of 2b and 3bmentioning

confidence: 99%

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Dinuclear Metallocenes with a Modulated Biphenylene Bridge for Olefin Polymerization

Kim

Lee

et al. 2007

Eur J Inorg Chem

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Dinuclear group 4 metallocene catalysts linked by a biphenylene or 1,2‐diphenylethylene bridge, namely [4,4′‐(C5Me4)2(C6H4)2][CpZrCl2]2 (2a), [p‐(C5Me4)C6H4CH2]2[CpZrCl2]2 (2b), [p‐(3,4‐Me2C5H2)C6H4CH2]2[CpZrCl2]2 (2c), [(C5Me4)2(C6H4)2][TiCl3]2 (3a), [p‐(C5Me4)C6H4CH2]2[TiCl3]2 (3b), and [p‐(3,4‐Me2C5H2)C6H4CH2]2[TiCl3]2 (3c), have been prepared and the crystal structures of 2b and 3b determined by X‐ray diffraction methods. The crystal structures reveal that these complexes consist of two equivalent metal units inverted with respect to the center of the bridge. All the complexes were tested for the polymerization of ethylene and styrene in the presence of methylaluminoxane (MAO), and direct comparisons of their catalytic properties with those of the corresponding mononuclear analogues [(PhC5Me4)CpZrCl2] (4a), [(p‐TolC5Me4)CpZrCl2] (4b), [(1‐p‐Tol‐3,4‐Me2C5H2)CpZrCl2] (4c), [(PhC5Me4)TiCl3] (5a), [(p‐TolC5Me4)TiCl3] (5b), and [(1‐p‐Tol‐3,4‐Me2C5H2)TiCl3] (5c) were performed. The dinuclear zirconocenes show a high activity in ethylene polymerization comparable with those of the corresponding mononuclear catalysts and give an increased molecular weight of polyethylene. The dinuclear half‐sandwich titanocenes exhibit similar or slightly lower activity and molecular weight in styrene polymerization compared with their mononuclear analogues. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

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Section: Introductionmentioning

confidence: 69%

Section: Complexes Synthesis and Characterizationmentioning

confidence: 99%

Section: X-ray Crystallographic Structures Of 2b and 3bmentioning

confidence: 99%

Section: X-ray Crystallographic Structures Of 2b and 3bmentioning

confidence: 99%

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Dinuclear Metallocenes with a Modulated Biphenylene Bridge for Olefin Polymerization

Kim

Lee

et al. 2007

Eur J Inorg Chem

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“…Phenylene [177][178][179]-, polymethylene [180][181][182]-, and silyl [183,184]-bridging moieties have all been shown to have some cooperative effects resulting in increased molecular weight or improved comonomer incorporation. Configurationally restrained ligands give an alternative to their flexible counterparts by maintaining proximate metal centres.…”

Section: Bimetallic Olefin Polymerisation Catalystsmentioning

confidence: 99%

Group 4 metal complexes for homogeneous olefin polymerisation: a short tutorial review

2015

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The discovery of transition metal-catalysed polymerisation of olefins in the 1950s by Ziegler and Natta was of huge importance. Over the last 30 years, the interest in homogenous polymerisation has not only grown but has changed focus from primarily studying the metallocene complexes of Group 4 to widespread exploration of postmetallocene systems. This is a consequence of extensive patenting of the metallocene catalyst systems, as well as for general interest in the improvement of polyolefin catalysis. The plastics industry produces more than 10 7 tonnes of polyethylene, polypropylene and polystyrene each year worldwide, and the study of well-defined homogenous catalysts is invaluable in uncovering the mechanism of polymerisation and the fundamental properties of the active species. This short Tutorial Review gives an overview of homogenous transition metal Ziegler-Natta catalysis in general as well as an overview of a selection of Group 4 post-metallocene catalysts. An overview of the synthesis and reactions of alkyl cations relevant to olefin polymerisation is also given. Finally, this review summarises recent advances in bimetallic catalysts for olefin polymerisation.

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Coordination Chemistry of Metal Phenolates—General Aspects

Doerrer

2014

Patai's Chemistry of Functional Groups

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An overview of metal phenolate chemistry is given that highlights the structural and functional diversity of contemporary chemistry between metals from all parts of the periodic table and aryloxide ligands. After a brief overview of synthetic methods, the review is organized using structural characterization, but is not exclusive of non‐structurally characterized species. Monodentate and polydentate ligands are described and organized by the type and number of donor atoms. Within each section, the chemistry is further subdivided by the periodic table s‐, p‐, d‐, and f‐blocks. Extensive references to the literature are provided for the interested reader.

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Biphenylene-Bridged Dinuclear Group 4 Metal Complexes: Enhanced Polymerization Properties in Olefin Polymerization

Abstract: The well-defined, novel dinuclear group 4 metal complexes [4,4′-(C 6 4) exhibit an increase of molecular weight as well as comparable or even higher catalytic activity in ethylene (2 and 4) and styrene (3 and 4) polymerization than their mononuclear counterparts.

Cited by 42 publications

References 23 publications

Dinuclear Metallocenes with a Modulated Biphenylene Bridge for Olefin Polymerization

Dinuclear Metallocenes with a Modulated Biphenylene Bridge for Olefin Polymerization

Group 4 metal complexes for homogeneous olefin polymerisation: a short tutorial review

Coordination Chemistry of Metal Phenolates—General Aspects

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