Metallocene-bridged [60]fullerene triads and cyclised metallocene-[60]fullerene diads are formed via [3 + 2] cycloaddition reactions of [60]fullerene with metallocene dialdehyde and an amino acid. In the case of cyclic diads only one regioisomer is formed, as determined by UV-vis and NMR spectroscopic studies. These compounds have both electron donor (metallocene) and acceptor ([60]fullerene) c...

Albert J. van Reenen and Omar Sultan Department of Chemistry and Polymer Science, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa Reprint requests to Dr. A. J. van Reenen. Fax: +27-21-8084967. E-mail: [email protected] Z. Naturforsch. 2007, 62b, 362 – 366; received November 1, 2006 Dedicated to Prof. Helgard G. Raubenheimer on the occasion of his 65th birthday TwoC2-symmet...

Beside Ziegler-Natta and Phillips catalysts the development of methylaluminoxane (MAO) as cocatalyst in combination with metallocenes or other transition metal complexes for the polymerization of olefins has widely increased the possibilities in controlling the polymer composition, polymer structure, tacticity and special properties with high precision. These catalysts allow the synthesis of is...

Syndiotactic polystyrene (SPS) refers to a type of thermoplastic material with phenyl substituents that are alternately chirally attached on both sides an aliphatic macromolecular main chain. Owing its excellent physical and mechanical properties, as well chemical stability, high transparency, electrical insulation characteristics, SPS is used in wide variety technical fields. commonly produced...

Copolymerization of ethylene with 1-hexene was carried out using two ansa-fluorenyl titanium derivative complexes. The substituent effect on the catalytic activity, monomer reactivity ratio and polymer property was investigated. It was found that the presence of t-Bu groups on fluorenyl ring exhibited remarkable catalytic activity and produced polymer with high molecular weight. However, these ...

Polypropylene (PP) random copolymers are an important class of commercial materials that can be tuned for a wide range different applications. The structure–property relations mainly discussed in this article focusing on two major influencing factors, the catalyst system and type amount comonomer. Ziegler–Natta (ZN) systems still dominate production polypropylene todays sixth-generation ZN cata...