Organometallic Catalysts and Olefin Polymerization

"Catalysis is more art than science", probably all of you have heard and even used this expression. Whether it is true or not, it alludes to the experience that new catalysts are hard to find, and near impossible to predict. Hard work and a lifetime of experience is invaluable. However, a keen mind might give insight into where to search, but not necessarily about where to find the answers. Historically, "quantum leaps" have often arisen from serendipity - we all know the story about the nickel-contaminated reactor that triggered further research towards the first coordination catalyst for ethene polymerization. Taking advan­ tage of this event, Karl Ziegler became the first chemist to earn both a Nobel prize and a fortune for the same invention. A broken NMR tube helped Walter Kaminsky discover the effect of high concentrations of methylaluminoxanes as co catalysts for metallocenes. When air reacted with the concentrated trim ethyl aluminum solution, sufficient amounts of methylaluminoxanes were formed, and the lazy catalyst dormant in the NMR tube suddenly became sensationally active. Ziegler and Kaminsky were lucky and had the genius needed to take advantage of their luck.

1. Group IV Catalysts and Cocatalysts.- UV/VIS Studies on the Activation of Zirconocene-Based Olefin-Polymerization Catalysts.- Activation of Siloxy-Substituted Compounds and Homopolymerisation of Ethylene by Different Soluble Alumoxane Cocatalysts.- Methylaluminoxane as a Cocatalyst for Olefin Polymerization. Structure, Reactivity and Cocatalytic Effect.- Olefin Polymerizationunder High-pressure: Formation of Super-high Molecular Weight Polyolefins.- Higher-Order Kinetics in Propene Polymerisations by Zirconocene Catalysts. Analysis of Alternative Reaction Mechanisms via a Genetic Algorithm.- Structures of MAO: Experimental Data and Molecular Models According to DFT Quantum-Chemical Simulations.- A DFT Study of Ethylene Polymerization by Zirconocene-Boron Catalytic Systems.- Activation Reactions of Cp2ZrCl2 and Cp2ZrMe2 with Aluminium Alkyl Type Cocatalysts Studied by in situ FTIR Spectroscopy.- Single Component Zirconocene Catalysts for the Stereospecific Polymerization of MMA.- Modeling Methylaluminoxane (MAO).- 2. Non Group IV Catalysts.- Phosphinoalkyl-Substituted Cyclopentadienyl Chromium Catalysts for the Oligomerization of Ethylene.- 1-Hexene Polymerization Initiated by ?- Diimine [N,N] Nickel Dibromide/MAO Catalytic Systems: Influence of the ?- Diimine Ligand Structure.- 1,3,5-Triazacyclohexane Complexes of Chromium as Homogeneous Model Systems for the Phillips Catalyst.- Rare Earth Half-Sandwich Catalysts for the Homo- and Copolymerization of Ethylene and Styrene.- 3. Traditional Catalysts.- The New Revolutionary Development of Catalysis as The Driving Force for the Commercial Dynamic Success of Polyolefins.- Basic Approaches for the Design of Active Sites on the Traditional Ziegler Catalysts.- Surface Analytical Approaches for the Phillips Catalyst by EPMA and XPS.- Main Kinetic Features of Ethylene Polymerization Reactions with Heterogeneous Ziegler-Natta Catalysts in the Light of Multi-Center Reaction Mechanism.- Hydrogen Effects in Propylene Polymerization with Ti-Based Ziegler-Natta Catalysts. Chemical Mechanism.- Elementary Steps of Ziegler-Natta Catalyst Intermediates Formation. In corporation of Magnesium Alkoxides with [Ti(dipp)4], Ph3SiOH, [A1(CH3)3] , and MC1(3)4 (M = V,Zr).- 4. Polymerization Mechanisms, Catalyst Structure and Polymer Structure Relationships.- Mechanistic Aspects of Olefin Polymerization with Metallocene Catalysts: Evidence from NMR Investigations.- Syndiotactic Specific Structures, Symmetry Considerations, Mechanistic Aspects.- The Particularities of Isospecific Polypropylene Synthesis in Bulk with Ansa-Metallocene Catalysts.- Ethene Polymerization Catalyzed by Monoalkyl and Methyl Substituted Zirconocenes. Possible Effects of Reaction Barriers and Ligand-Metal Agostic Interactions.- A Density Fuctional Theroy Study of the Syndiotactic-Specific Polymerization of Styrene.- Influence of Ligands on the Deactivation of Group IV Metallocene Catalysts in t h e High-Temperature Polymerization of Ethene.- 5. Polymerization, Co-Polymerization, Non-Traditional Monomers and Polymer Characterization.- Correlations Between Chain Branching, Morphology Development and Properties of Polyethenes.- Heterogenized Bifunctional Catalysts in Olefin Polymerization.- Long-Chain Branched Polyethene via Metallocene-Catalysis: Comparison of Catalysts.- New Half-Sandwich Titanocenes for the Polymerization of Butadiene.- Metallocene Catalyzed Copolymerization of Propene with Mono and Diolefins.- A Comparison of the Behavior of Nickel/MAO Catalytic Systems in the Polymerization of Styrene and 1,3-Cyclohexadiene.- 6. Catalyst Heterogenizationand Particle Microreactor Effects.- Activity Limits of Heterogeneous Polymerization Catalysts.- Reversibly Crosslinked Polystyrene as a Support for Metallocenes Part I: Covalently Bonded Metaollocenes a n d Functionalized Supports.- Reversibly Crosslinked Polystyrene as a Support for Metallocenes Part II: Non-Covalent Bonding for the Immobilization.- An Intrinsic Defect of Slow Monomer Diffusion Theroy for Explaining Broad MWDs.- Prepolymerization and Copolymerization Studies Using Homogeneous and Silica-supported Cp2ZrCl2/MAO Catalyst Systems.- Unique Flowability Behavior of Ethylene Copolymers Produced by a Catalyst System Comprising Ethylenebis(indenyl)hafnium Dichloride and Aluminoxane.- Diffusion Measurements in Porous Polymer Particles.