Various iron dichloride complexes with aliphatic and aromatic bidentate amine ligands have been synthesized and used, in combination with aluminium-compounds (AlR3 or methylaluminoxane), for the polymerization of 1,3-dienes. Catalyst activity, chemo- and stereoselectivity are strongly influenced by the type of ligand; systems based on iron complexes with aromatic bidentate amines (e.g. bypiridine or phenantroline), in particular, exhibit an extremely high activity, giving from butadiene a 1,2 syndiotactic polymer. These systems are also able to polymerize substituted butadienes (e.g. isoprene, (E)-1,3-pentadiene, 2,3-dimethyl-1,3-butadiene) giving polymers with different structure from the different monomers; these results have permitted to confirm some aspects of the polymerization mechanism previously proposed.
Polymerization of 1,3-dienes with iron complexes based catalysts. Influence of the ligand on catalyst activity and stereospecificity
Ricci G;
2003
Abstract
Various iron dichloride complexes with aliphatic and aromatic bidentate amine ligands have been synthesized and used, in combination with aluminium-compounds (AlR3 or methylaluminoxane), for the polymerization of 1,3-dienes. Catalyst activity, chemo- and stereoselectivity are strongly influenced by the type of ligand; systems based on iron complexes with aromatic bidentate amines (e.g. bypiridine or phenantroline), in particular, exhibit an extremely high activity, giving from butadiene a 1,2 syndiotactic polymer. These systems are also able to polymerize substituted butadienes (e.g. isoprene, (E)-1,3-pentadiene, 2,3-dimethyl-1,3-butadiene) giving polymers with different structure from the different monomers; these results have permitted to confirm some aspects of the polymerization mechanism previously proposed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
