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Journal ArticleDOI

Synthesis, Structures, Bonding, and Ethylene Reactivity of Group 4 Metal Alkyl Complexes Incorporating 8-Quinolinolato Ligands

22 Jul 1997-Organometallics (American Chemical Society)-Vol. 16, Iss: 15, pp 3282-3302
TL;DR: In this article, the synthesis, structures, bonding, and reactivity of neutral (Ox)2MR2 and cationic (O2MR+ zirconium and hafnium alkyl complexes which contain substituted 8-quinolinolato ligands are described.
About: This article is published in Organometallics.The article was published on 1997-07-22. It has received 160 citations till now. The article focuses on the topics: Alkyl & Ligand.
Citations
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Patent
Rex Eugene Murray1
01 Jul 1998
TL;DR: In this paper, a cyclic catalyst precursor with formula (1) wherein M is a Group IVB metal, each L is a monovalent, bivalent, or trivalent anion, X and Y are each heteroatoms, and each cyclo is a Cyclic moiety; each R1 is a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group IIIA to Group VIIA elements.
Abstract: A catalyst precursor having formula (1) wherein M is a Group IVB metal; each L is a monovalent, bivalent, or trivalent anion; X and Y are each heteroatoms; each Cyclo is a cyclic moiety; each R1 is a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group IIIA to Group VIIA elements, and two or more adjacent R1 groups may be joined to form a cyclic moiety; each R2 is a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group IIIA to Group VIIA elements, and two or more adjacent R2 groups may be joined to form a cyclic moiety; W is a bridging group; and each m is independently an integer from 0 to 5.

280 citations

Journal ArticleDOI
TL;DR: In this paper, a family of chelating amine bis(phenolate) zirconium dibenzyl complexes were synthesized in quantitative yields from a versatile family of amine−bis((2-hydroxyaryl)methyl) precursors, their X-ray structures solved, and their reactivity in the polymerization of 1hexene in the presence of B(C6F5)3 studied.

256 citations

Journal ArticleDOI
TL;DR: In this paper, the Entdeckung einer Klasse hochaktiver Eisenkatalysatoren 1 was beleuchtet, angesichts der Tatsache, das Eisen auf diesem Gebiet bis dahin vollig bedeutungslos war.
Abstract: Auch Komplexe spater Ubergangsmetalle sind aktive und selektive Katalysatoren fur die Polymerisation von α-Olefinen. Die Entdeckung einer Klasse hochaktiver Eisenkatalysatoren 1 beleuchtet, angesichts der Tatsache, das Eisen auf diesem Gebiet bis dahin vollig bedeutungslos war, die Moglichkeiten zur Entdeckung neuer Katalysatoren. Entdeckungen wie diese losten in den letzten Jahren sowohl in Universitats- als auch in Industrielaboratorien eine intensive Suche nach neuen Katalysatoren aus. R1 = H, Me; R2 = Me, iPr; R3 = H, Me, iPr; R4 = H, Me; X = Halogen.

219 citations

Journal ArticleDOI
TL;DR: In this article, the pyridine ring ortho positi... was methylated with a stoichiometric amount of methyl alumoxane (PMAO) in toluene.
Abstract: Reaction of {2,6-bis[2,6-(i-Pr)2PhNC(Me)]2(C5H3N)}VCl3·1.3(CH2Cl2) (1) with stoichiometric amount of methyl alumoxane (PMAO) in toluene resulted in the methylation of the pyridine ring ortho positi...

195 citations

References
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Book
01 Jan 1977
TL;DR: Molecular Orbitals and Frontier Orbitals.
Abstract: Molecular Orbitals and Frontier Orbitals. Ionic Reactions. Thermal Pericyclic Reactions. Radical Reactions. Photochemical Reactions. Exceptions.

2,548 citations

Journal ArticleDOI
TL;DR: The synthesis and structure of the title compound were described in this article, where the synthesis and the structure of a molecule of toluene per scandium in the monoclinic system, space group C2/c, was described.

491 citations

Journal ArticleDOI
TL;DR: In the 40 years since the discovery of transition metal catalysts for olefin polymerization by Ziegler and Natta, a substantial amount of research has been directed toward understanding the basic mechanistic steps of this important industrial process.
Abstract: In the 40 years since the discovery of transition metal catalysts for olefin polymerization by Ziegler and Natta a substantial amount of research has been directed toward understanding the basic mechanistic steps of this important industrial process. Attention has focused in particular on the process of monomer enchainment, which is generally agreed to occur through olefin coordination followed by insertion into a metal-carbon bond. Four general mechanistic proposals for the nature of this insertion have emerged (Scheme 1). The first is alkyl migration to the coordinated olefin and is known as the Cossee-Arlman mechanism. The second model, proposed by Rooney and Green, involves an oxidative 1,2-hydrogen shift from the R-carbon of the polymer chain, generating a metal-alkylidene hydride. This species then reacts with an olefin to generate a metallacyclobutane, and reductive elimination completes the propagation sequence. Somewhat intermediate to the first two proposals is a mechanism proposed by Green, Rooney, and Brookhart where a hydrogen atom on the R-carbon of the growing polymer chain interacts with the metal center throughout the catalytic cycle. This three-center, two-electron covalent bond, termed an “agostic interaction”, occurs when the hydrogen atom is simultaneously bonded to both a carbon and a metal atom. The fourth mechanistic possibility is olefin insertion where an R-hydrogen interacts with the metal center only during the transition state of the C-C bond forming step. This mechanism is a hybrid of the Cossee-Arlman and modified Green-Rooney mechanisms.

287 citations

Journal ArticleDOI
TL;DR: In this article, the physical properties and reactivity of the precursors of Ti(CH 2 C 6 H 5 ) 4 (I), Zr(CH2 C 6H 5 ) (IX) and their halogen and alkoxy derivatives are described.

271 citations