The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
C 1 -Bridged fluorenylidene cyclopentadienylidene complexes of the type (C 13 H 8 -CR 1 R 2 -C 5 H 3 R)ZrCl 2 (R 1 , R 2 =alkyl, phenyl, alkenyl; R=H, alkyl, alkenyl, substituted silyl) as catalyst precursors for the polymerization of ethylene and propylene
The synthesis and characterization of 14 new C 1 -bridged fluorenylidene cyclopentadienylidene complexes of zirconium is described. After activation with methylaluminoxane (MAO), these metallocene complexes can be used for the polymerization of ethylene and propylene. Various substituents in the bridge and in position 3 of the cyclopentadienylidene ligand have a strong influence on the activity of the corresponding catalysts and the molecular weights of the formed polyolefins. The bulkiness of the substituents in position 3 of the cyclopentadienylidene ring determines the extent of the stereospecific polymerization of propylene. Substituents can be selected that produce hemitactic, syndiotactic or isotactic polypropylenes and/or the corresponding block copolymers.