Objectif A variety of organometallic titanium, zirconium, and hafnium systems containing cyclopentadienyl ligands were used for the generation of very reactive and selective homogenous Ziegler type catalysts. These catalysts were used for the polymerization of propene. Most of the catalysts systems generated by the action of the oligomeric methyl alumoxane reagent with these cyclopentadienyl group 4 metal complexes were extremely reactive. Many produced highly isotactic polypropylene. A variety of specific types of substituted cyclopentadienyl derived ligand systems were also developed along with a number of new catalyst precursors including fulvene type ligands. A number of novel systems of this type were generated and it was found that the catalysts derived from them were very active. The chemistry of mono(cyclopentadienyl)zirconium and mono(cyclopentadienyl)hafnium complexes was studied and a variety of novel types of such compounds were then developed resulting in the formation of chiral variants of hydrocarbyl annulated cyclopentadienyl ligands that are of great use in asymmetric catalysis. The optically active (dibornacyclopentadienyl)zirconiumtrichloride was used as an organometallic Lewis acid catalyst in very effective asymmetric hydroxalkylation processes of electron rich hydroxyarene systems. A trifluoromethyl derivative of the dibornacyclopentadienyl ligand system has also been prepared. X-ray crystallographic results gave an in depth insight into the stereochemical action of this novel catalyst type. Based on the results of the X-ray crystal structure analysis of the (dibornacyclopentadienyl)zirconiumtrichloride system it was possible to asign a singe transition state geometry to the favoured pathway of product formation in this catalytic system. A variety of substituted indenylligand, tetrahydroindenylligand, and cyclopentadienylligand systems were developed which bear chiral substituents that originate from the terpene or steroid series. Attachment of these novel ligand systems to a group 4 transition metal resulted in the formation of optically pure metal complexes. Extremely reactive and selective homogeneous Ziegler catalysts were then generated for the stereoselective polymerization of olefins.Novel synthetic entries to mono (cyclopentadienyl) complexes of the group 4-6 transition metals shall be developed. The (RCp) M complexes will be used as stoichiometric reagents in organic syntheses (synselective aldol reaction; modification of nucleophilic reagents). Main emphasis is put into the use of the (RCp) M complexes for developing new catalysts for preparing organic products by carbon-carbon coupling induced by organometallic radicals or via Ziegler-Natta-type catalysis. Champ scientifique natural scienceschemical sciencesinorganic chemistryorganometallic chemistrynatural scienceschemical sciencesinorganic chemistrytransition metalsnatural scienceschemical sciencesorganic chemistryhydrocarbonsnatural scienceschemical sciencescatalysisnatural sciencesmathematicspure mathematicsgeometry Programme(s) FP2-SCIENCE - Programme plan (EEC) to stimulate the international cooperation and interchange needed by European research scientists (SCIENCE), 1988-1992 Thème(s) Data not available Appel à propositions Data not available Régime de financement CSC - Cost-sharing contracts Coordinateur WESTFAELISCHE WILHELMS-UNIVERSITAET MUENSTER Contribution de l’UE Aucune donnée Adresse RONTGENSTRASSE 9-13 48149 MUENSTER Allemagne Voir sur la carte Coût total Aucune donnée Participants (3) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire NETHERLANDS RESEARCH SCHOOL FOR ASTRONOMY - LEGALLY REPRESENTED BY UNIVERSITY OF GRONINGEN Pays-Bas Contribution de l’UE Aucune donnée Adresse 5,Broerstraat 5 9712 CP GRONINGEN Voir sur la carte Coût total Aucune donnée THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE Royaume-Uni Contribution de l’UE Aucune donnée Adresse Trinity Lane, The Old Schools, CB2 1TN CAMBRIDGE Voir sur la carte Coût total Aucune donnée UNIVERSITY OF ALCALA Espagne Contribution de l’UE Aucune donnée Adresse S/N,Plaza de San Diego S/N (Colegio de San Idelfonso) 28801 ALCALA DE HENARES Voir sur la carte Coût total Aucune donnée
